Network Working Group                                              M. Ko
Request for Comments: 5046                               IBM Corporation
Category: Standards Track                                 M. Chadalapaka
                                                 Hewlett-Packard Company
                                                              J. Hufferd
                                                           Brocade, Inc.
                                                                U. Elzur
                                                                 H. Shah
                                                               P. Thaler
                                                    Broadcom Corporation
                                                            October 2007
        
Network Working Group                                              M. Ko
Request for Comments: 5046                               IBM Corporation
Category: Standards Track                                 M. Chadalapaka
                                                 Hewlett-Packard Company
                                                              J. Hufferd
                                                           Brocade, Inc.
                                                                U. Elzur
                                                                 H. Shah
                                                               P. Thaler
                                                    Broadcom Corporation
                                                            October 2007
        

Internet Small Computer System Interface (iSCSI) Extensions for Remote Direct Memory Access (RDMA)

用于远程直接内存访问(RDMA)的Internet小型计算机系统接口(iSCSI)扩展

Status of This Memo

关于下段备忘

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

本文件规定了互联网社区的互联网标准跟踪协议,并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态,请参考当前版本的“互联网官方协议标准”(STD 1)。本备忘录的分发不受限制。

Abstract

摘要

Internet Small Computer System Interface (iSCSI) Extensions for Remote Direct Memory Access (RDMA) provides the RDMA data transfer capability to iSCSI by layering iSCSI on top of an RDMA-Capable Protocol, such as the iWARP protocol suite. An RDMA-Capable Protocol provides RDMA Read and Write services, which enable data to be transferred directly into SCSI I/O Buffers without intermediate data copies. This document describes the extensions to the iSCSI protocol to support RDMA services as provided by an RDMA-Capable Protocol, such as the iWARP protocol suite.

用于远程直接内存访问(RDMA)的Internet小型计算机系统接口(iSCSI)扩展通过将iSCSI分层到支持RDMA的协议(如iWARP协议套件)之上,向iSCSI提供RDMA数据传输能力。支持RDMA的协议提供RDMA读写服务,使数据能够直接传输到SCSI I/O缓冲区,而无需中间数据拷贝。本文档介绍了iSCSI协议的扩展,以支持支持支持RDMA的协议(如iWARP协议套件)提供的RDMA服务。

Table of Contents

目录

   1. Introduction ....................................................5
      1.1. Motivation .................................................5
      1.2. Architectural Goals ........................................6
      1.3. Protocol Overview ..........................................7
      1.4. RDMA Services and iSER .....................................8
           1.4.1. STag ................................................8
           1.4.2. Send ................................................9
           1.4.3. RDMA Write ..........................................9
           1.4.4. RDMA Read ...........................................9
      1.5. SCSI Read Overview ........................................10
      1.6. SCSI Write Overview .......................................10
      1.7. iSCSI/iSER Layering .......................................10
   2. Definitions and Acronyms .......................................11
      2.1. Definitions ...............................................11
      2.2. Acronyms ..................................................17
      2.3. Conventions ...............................................19
   3. Upper Layer Interface Requirements .............................19
      3.1. Operational Primitives Offered by iSER ....................20
           3.1.1. Send_Control .......................................20
           3.1.2. Put_Data ...........................................20
           3.1.3. Get_Data ...........................................21
           3.1.4. Allocate_Connection_Resources ......................21
           3.1.5. Deallocate_Connection_Resources ....................22
           3.1.6. Enable_Datamover ...................................22
           3.1.7. Connection_Terminate ...............................22
           3.1.8. Notice_Key_Values ..................................23
           3.1.9. Deallocate_Task_Resources ..........................23
      3.2. Operational Primitives Used by iSER .......................23
           3.2.1. Control_Notify .....................................24
           3.2.2. Data_Completion_Notify .............................24
           3.2.3. Data_ACK_Notify ....................................24
           3.2.4. Connection_Terminate_Notify ........................25
      3.3. iSCSI Protocol Usage Requirements .........................25
   4. Lower Layer Interface Requirements .............................26
      4.1. Interactions with the RCaP Layer ..........................26
      4.2. Interactions with the Transport Layer .....................27
   5. Connection Setup and Termination ...............................27
      5.1. iSCSI/iSER Connection Setup ...............................27
           5.1.1. Initiator Behavior .................................29
           5.1.2. Target Behavior ....................................30
           5.1.3. iSER Hello Exchange ................................32
      5.2. iSCSI/iSER Connection Termination .........................33
           5.2.1. Normal Connection Termination at the Initiator .....33
           5.2.2. Normal Connection Termination at the Target ........34
           5.2.3. Termination without Logout Request/Response PDUs ...34
        
   1. Introduction ....................................................5
      1.1. Motivation .................................................5
      1.2. Architectural Goals ........................................6
      1.3. Protocol Overview ..........................................7
      1.4. RDMA Services and iSER .....................................8
           1.4.1. STag ................................................8
           1.4.2. Send ................................................9
           1.4.3. RDMA Write ..........................................9
           1.4.4. RDMA Read ...........................................9
      1.5. SCSI Read Overview ........................................10
      1.6. SCSI Write Overview .......................................10
      1.7. iSCSI/iSER Layering .......................................10
   2. Definitions and Acronyms .......................................11
      2.1. Definitions ...............................................11
      2.2. Acronyms ..................................................17
      2.3. Conventions ...............................................19
   3. Upper Layer Interface Requirements .............................19
      3.1. Operational Primitives Offered by iSER ....................20
           3.1.1. Send_Control .......................................20
           3.1.2. Put_Data ...........................................20
           3.1.3. Get_Data ...........................................21
           3.1.4. Allocate_Connection_Resources ......................21
           3.1.5. Deallocate_Connection_Resources ....................22
           3.1.6. Enable_Datamover ...................................22
           3.1.7. Connection_Terminate ...............................22
           3.1.8. Notice_Key_Values ..................................23
           3.1.9. Deallocate_Task_Resources ..........................23
      3.2. Operational Primitives Used by iSER .......................23
           3.2.1. Control_Notify .....................................24
           3.2.2. Data_Completion_Notify .............................24
           3.2.3. Data_ACK_Notify ....................................24
           3.2.4. Connection_Terminate_Notify ........................25
      3.3. iSCSI Protocol Usage Requirements .........................25
   4. Lower Layer Interface Requirements .............................26
      4.1. Interactions with the RCaP Layer ..........................26
      4.2. Interactions with the Transport Layer .....................27
   5. Connection Setup and Termination ...............................27
      5.1. iSCSI/iSER Connection Setup ...............................27
           5.1.1. Initiator Behavior .................................29
           5.1.2. Target Behavior ....................................30
           5.1.3. iSER Hello Exchange ................................32
      5.2. iSCSI/iSER Connection Termination .........................33
           5.2.1. Normal Connection Termination at the Initiator .....33
           5.2.2. Normal Connection Termination at the Target ........34
           5.2.3. Termination without Logout Request/Response PDUs ...34
        
   6. Login/Text Operational Keys ....................................35
      6.1. HeaderDigest and DataDigest ...............................35
      6.2. MaxRecvDataSegmentLength ..................................36
      6.3. RDMAExtensions ............................................36
      6.4. TargetRecvDataSegmentLength ...............................37
      6.5. InitiatorRecvDataSegmentLength ............................38
      6.6. OFMarker and IFMarker .....................................38
      6.7. MaxOutstandingUnexpectedPDUs ..............................38
   7. iSCSI PDU Considerations .......................................39
      7.1. iSCSI Data-Type PDU .......................................39
      7.2. iSCSI Control-Type PDU ....................................40
      7.3. iSCSI PDUs ................................................40
           7.3.1. SCSI Command .......................................40
           7.3.2. SCSI Response ......................................42
           7.3.3. Task Management Function Request/Response ..........44
           7.3.4. SCSI Data-Out ......................................45
           7.3.5. SCSI Data-In .......................................46
           7.3.6. Ready to Transfer (R2T) ............................48
           7.3.7. Asynchronous Message ...............................50
           7.3.8. Text Request and Text Response .....................50
           7.3.9. Login Request and Login Response ...................50
           7.3.10. Logout Request and Logout Response ................51
           7.3.11. SNACK Request .....................................51
           7.3.12. Reject ............................................51
           7.3.13. NOP-Out and NOP-In ................................51
   8. Flow Control and STag Management ...............................52
      8.1. Flow Control for RDMA Send Message Types ..................52
           8.1.1. Flow Control for Control-Type PDUs from the
                  Initiator ..........................................52
           8.1.2. Flow Control for Control-Type PDUs from the
                  Target .............................................55
      8.2. Flow Control for RDMA Read Resources ......................56
      8.3. STag Management ...........................................56
           8.3.1. Allocation of STags ................................57
           8.3.2. Invalidation of STags ..............................57
   9. iSER Control and Data Transfer .................................58
      9.1. iSER Header Format ........................................58
      9.2. iSER Header Format for the iSCSI Control-Type PDU .........59
      9.3. iSER Header Format for the iSER Hello Message .............60
      9.4. iSER Header Format for the iSER HelloReply Message ........61
      9.5. SCSI Data Transfer Operations .............................62
           9.5.1. SCSI Write Operation ...............................62
           9.5.2. SCSI Read Operation ................................63
           9.5.3. Bidirectional Operation ............................64
   10. iSER Error Handling and Recovery ..............................64
      10.1. Error Handling ...........................................64
           10.1.1. Errors in the Transport Layer .....................64
           10.1.2. Errors in the RCaP Layer ..........................65
        
   6. Login/Text Operational Keys ....................................35
      6.1. HeaderDigest and DataDigest ...............................35
      6.2. MaxRecvDataSegmentLength ..................................36
      6.3. RDMAExtensions ............................................36
      6.4. TargetRecvDataSegmentLength ...............................37
      6.5. InitiatorRecvDataSegmentLength ............................38
      6.6. OFMarker and IFMarker .....................................38
      6.7. MaxOutstandingUnexpectedPDUs ..............................38
   7. iSCSI PDU Considerations .......................................39
      7.1. iSCSI Data-Type PDU .......................................39
      7.2. iSCSI Control-Type PDU ....................................40
      7.3. iSCSI PDUs ................................................40
           7.3.1. SCSI Command .......................................40
           7.3.2. SCSI Response ......................................42
           7.3.3. Task Management Function Request/Response ..........44
           7.3.4. SCSI Data-Out ......................................45
           7.3.5. SCSI Data-In .......................................46
           7.3.6. Ready to Transfer (R2T) ............................48
           7.3.7. Asynchronous Message ...............................50
           7.3.8. Text Request and Text Response .....................50
           7.3.9. Login Request and Login Response ...................50
           7.3.10. Logout Request and Logout Response ................51
           7.3.11. SNACK Request .....................................51
           7.3.12. Reject ............................................51
           7.3.13. NOP-Out and NOP-In ................................51
   8. Flow Control and STag Management ...............................52
      8.1. Flow Control for RDMA Send Message Types ..................52
           8.1.1. Flow Control for Control-Type PDUs from the
                  Initiator ..........................................52
           8.1.2. Flow Control for Control-Type PDUs from the
                  Target .............................................55
      8.2. Flow Control for RDMA Read Resources ......................56
      8.3. STag Management ...........................................56
           8.3.1. Allocation of STags ................................57
           8.3.2. Invalidation of STags ..............................57
   9. iSER Control and Data Transfer .................................58
      9.1. iSER Header Format ........................................58
      9.2. iSER Header Format for the iSCSI Control-Type PDU .........59
      9.3. iSER Header Format for the iSER Hello Message .............60
      9.4. iSER Header Format for the iSER HelloReply Message ........61
      9.5. SCSI Data Transfer Operations .............................62
           9.5.1. SCSI Write Operation ...............................62
           9.5.2. SCSI Read Operation ................................63
           9.5.3. Bidirectional Operation ............................64
   10. iSER Error Handling and Recovery ..............................64
      10.1. Error Handling ...........................................64
           10.1.1. Errors in the Transport Layer .....................64
           10.1.2. Errors in the RCaP Layer ..........................65
        
           10.1.3. Errors in the iSER Layer ..........................66
           10.1.4. Errors in the iSCSI Layer .........................67
      10.2. Error Recovery ...........................................69
           10.2.1. PDU Recovery ......................................69
           10.2.2. Connection Recovery ...............................70
   11. Security Considerations .......................................71
   12. References ....................................................71
      12.1. Normative References .....................................71
      12.2. Informative References ...................................72
   Appendix A. iWARP Message Format for iSER .........................73
      A.1. iWARP Message Format for iSER Hello Message ...............73
      A.2. iWARP Message Format for iSER HelloReply Message ..........74
      A.3. iWARP Message Format for SCSI Read Command PDU ............75
      A.4. iWARP Message Format for SCSI Read Data ...................76
      A.5. iWARP Message Format for SCSI Write Command PDU ...........77
      A.6. iWARP Message Format for RDMA Read Request ................78
      A.7. iWARP Message Format for Solicited SCSI Write Data ........79
      A.8. iWARP Message Format for SCSI Response PDU ................80
   Appendix B. Architectural Discussion of iSER over InfiniBand ......81
      B.1. The Host Side of the iSCSI and iSER Connections
           in InfiniBand .............................................81
      B.2. The Storage Side of the iSCSI and iSER Mixed
           Network Environment .......................................82
      B.3. Discovery Processes for an InfiniBand Host ................82
      B.4. IBTA Connection Specifications ............................83
   Acknowledgments ...................................................83
        
           10.1.3. Errors in the iSER Layer ..........................66
           10.1.4. Errors in the iSCSI Layer .........................67
      10.2. Error Recovery ...........................................69
           10.2.1. PDU Recovery ......................................69
           10.2.2. Connection Recovery ...............................70
   11. Security Considerations .......................................71
   12. References ....................................................71
      12.1. Normative References .....................................71
      12.2. Informative References ...................................72
   Appendix A. iWARP Message Format for iSER .........................73
      A.1. iWARP Message Format for iSER Hello Message ...............73
      A.2. iWARP Message Format for iSER HelloReply Message ..........74
      A.3. iWARP Message Format for SCSI Read Command PDU ............75
      A.4. iWARP Message Format for SCSI Read Data ...................76
      A.5. iWARP Message Format for SCSI Write Command PDU ...........77
      A.6. iWARP Message Format for RDMA Read Request ................78
      A.7. iWARP Message Format for Solicited SCSI Write Data ........79
      A.8. iWARP Message Format for SCSI Response PDU ................80
   Appendix B. Architectural Discussion of iSER over InfiniBand ......81
      B.1. The Host Side of the iSCSI and iSER Connections
           in InfiniBand .............................................81
      B.2. The Storage Side of the iSCSI and iSER Mixed
           Network Environment .......................................82
      B.3. Discovery Processes for an InfiniBand Host ................82
      B.4. IBTA Connection Specifications ............................83
   Acknowledgments ...................................................83
        

Table of Figures

图表

   Figure 1. Example of iSCSI/iSER Layering in Full Feature Phase ....11
   Figure 2. iSER Header Format ......................................58
   Figure 3. iSER Header Format for iSCSI Control-Type PDU ...........59
   Figure 4. iSER Header Format for iSER Hello Message ...............60
   Figure 5. iSER Header Format for iSER HelloReply Message ..........61
   Figure 6. SendSE Message containing an iSER Hello Message .........72
   Figure 7. SendSE Message containing an iSER HelloReply Message ....74
   Figure 8. SendSE Message containing a SCSI Read Command PDU .......75
   Figure 9. RDMA Write Message containing SCSI Read Data ............76
   Figure 10. SendSE Message containing a SCSI Write Command PDU .....77
   Figure 11. RDMA Read Request Message ..............................78
   Figure 12. RDMA Read Response Message containing SCSI Write Data ..79
   Figure 13. SendInvSE Message containing SCSI Response PDU .........80
   Figure 14. iSCSI and iSER on IB ...................................81
   Figure 15. Storage Controller with TCP, iWARP, and IB Connections .82
        
   Figure 1. Example of iSCSI/iSER Layering in Full Feature Phase ....11
   Figure 2. iSER Header Format ......................................58
   Figure 3. iSER Header Format for iSCSI Control-Type PDU ...........59
   Figure 4. iSER Header Format for iSER Hello Message ...............60
   Figure 5. iSER Header Format for iSER HelloReply Message ..........61
   Figure 6. SendSE Message containing an iSER Hello Message .........72
   Figure 7. SendSE Message containing an iSER HelloReply Message ....74
   Figure 8. SendSE Message containing a SCSI Read Command PDU .......75
   Figure 9. RDMA Write Message containing SCSI Read Data ............76
   Figure 10. SendSE Message containing a SCSI Write Command PDU .....77
   Figure 11. RDMA Read Request Message ..............................78
   Figure 12. RDMA Read Response Message containing SCSI Write Data ..79
   Figure 13. SendInvSE Message containing SCSI Response PDU .........80
   Figure 14. iSCSI and iSER on IB ...................................81
   Figure 15. Storage Controller with TCP, iWARP, and IB Connections .82
        
1. Introduction
1. 介绍
1.1. Motivation
1.1. 动机

The iSCSI protocol [RFC3720] is a mapping of the SCSI Architecture Model (see [SAM2]) over the TCP protocol. SCSI commands are carried by iSCSI requests, and SCSI responses and status are carried by iSCSI responses. Other iSCSI protocol exchanges and SCSI data are also transported in iSCSI Protocol Data Units (PDUs).

iSCSI协议[RFC3720]是SCSI体系结构模型(参见[SAM2])在TCP协议上的映射。SCSI命令由iSCSI请求承载,SCSI响应和状态由iSCSI响应承载。其他iSCSI协议交换和SCSI数据也在iSCSI协议数据单元(PDU)中传输。

Out-of-order TCP segments in the Traditional iSCSI model have to be stored and reassembled before the iSCSI protocol layer within an end node can place the data in the iSCSI buffers. This reassembly is required because not every TCP segment is likely to contain an iSCSI header to enable its placement, and TCP itself does not have a built-in mechanism for signaling Upper Level Protocol (ULP) message boundaries to aid placement of out-of-order segments. This TCP reassembly at high network speeds is quite counter-productive for the following reasons: wasted memory bandwidth in data copying, the need for reassembly memory, wasted CPU cycles in data copying, and the general store-and-forward latency from an application perspective. TCP reassembly was recognized as a serious issue in [RFC3720], and the notion of a "sync and steering layer" was introduced that is optional to implement and use. One specific sync and steering mechanism, called "markers", was defined in [RFC3720], which provides an application-level way of framing iSCSI Protocol Data Units (PDUs) within the TCP data stream even when the TCP segments are not yet reassembled to be in-order.

在终端节点内的iSCSI协议层将数据放入iSCSI缓冲区之前,必须存储和重新组装传统iSCSI模型中的无序TCP段。之所以需要重新组装,是因为并非每个TCP段都可能包含iSCSI头以支持其放置,而且TCP本身也没有内置机制,用于向上层协议(ULP)消息边界发送信号以帮助放置无序段。这种在高网络速度下进行的TCP重组会适得其反,原因如下:数据复制中浪费的内存带宽、重组内存的需要、数据复制中浪费的CPU周期,以及应用程序角度的一般存储和转发延迟。在[RFC3720]中,TCP重组被认为是一个严重的问题,并且引入了“同步和指导层”的概念,该层是可选的实现和使用。[RFC3720]中定义了一种称为“标记器”的特定同步和控制机制,该机制提供了一种应用程序级方式,即使在TCP段尚未按顺序重新组装时,也可以在TCP数据流中构建iSCSI协议数据单元(PDU)。

With these defined techniques in [RFC3720], a Network Interface Controller customized for iSCSI (SNIC) could offload the TCP/IP processing and support direct data placement, but most iSCSI implementations do not support iSCSI "markers", making SNIC marker-based direct data placement unusable in practice.

使用[RFC3720]中定义的这些技术,为iSCSI定制的网络接口控制器(SNIC)可以卸载TCP/IP处理并支持直接数据放置,但大多数iSCSI实施不支持iSCSI“标记”,使得基于SNIC标记的直接数据放置在实践中无法使用。

The iWARP protocol stack provides direct data placement functionality that is usable in practice. In addition, there is interest in using iSCSI with other Remote Direct Memory Access (RDMA) protocol stacks that support direct data placement, such as the one provided by InfiniBand. The generic term RDMA-Capable Protocol (RCaP) is used to refer to the RDMA functionality provided by such protocol stacks.

iWARP协议栈提供了实际可用的直接数据放置功能。此外,人们还希望将iSCSI与其他支持直接数据放置的远程直接内存访问(RDMA)协议栈(如InfiniBand提供的协议栈)一起使用。通用术语RDMA能力协议(RCaP)用于指由此类协议栈提供的RDMA功能。

With the availability of RDMA-Capable Controllers within a host system, which does not have SNICs, it is appropriate for iSCSI to be able to exploit the direct data placement function of the RDMA-Capable Controller like other applications.

在没有SNIC的主机系统中提供支持RDMA的控制器后,iSCSI可以像其他应用程序一样利用支持RDMA的控制器的直接数据放置功能。

iSCSI Extensions for RDMA (iSER) is designed precisely to take advantage of generic RDMA technologies -- iSER's goal is to permit iSCSI to employ direct data placement and RDMA capabilities using a generic RDMA-Capable Controller. In summary, the iSCSI/iSER protocol stack is designed to enable scaling to high speeds by relying on a generic data placement process and RDMA technologies and products, which enable direct data placement of both in-order and out-of-order data.

用于RDMA的iSCSI扩展(iSER)正是为了利用通用RDMA技术而设计的—iSER的目标是允许iSCSI使用支持RDMA的通用控制器来采用直接数据放置和RDMA功能。总之,iSCSI/iSER协议栈的设计目的是通过依赖通用数据放置过程和RDMA技术及产品来实现高速扩展,这些技术和产品可以直接放置有序和无序数据。

This document describes iSER as a protocol extension to iSCSI, both for convenience of description and because it is true in a very strict protocol sense. However, note that iSER is in reality extending the connectivity of the iSCSI protocol defined in [RFC3720], and the name iSER reflects this reality.

本文档将iSER描述为iSCSI的协议扩展,这既是为了便于描述,也是因为它在非常严格的协议意义上是正确的。但是,请注意,iSER实际上是在扩展[RFC3720]中定义的iSCSI协议的连接,iSER的名称反映了这一现实。

When the iSCSI protocol as defined in [RFC3720] (i.e., without the iSER enhancements) is intended in the rest of the document, the term "Traditional iSCSI" is used to make the intention clear.

当[RFC3720]中定义的iSCSI协议(即,没有iSER增强)在本文档的其余部分中使用时,使用术语“传统iSCSI”来明确其用途。

1.2. Architectural Goals
1.2. 建筑目标

This section summarizes the architectural goals that guided the design of iSER.

本节总结了指导iSER设计的体系结构目标。

1. Provide an RDMA data transfer model for iSCSI that enables direct in-order or out-of-order data placement of SCSI data into pre-allocated SCSI buffers while maintaining in-order data delivery.

1. 提供一种用于iSCSI的RDMA数据传输模型,该模型支持将SCSI数据直接按顺序或按顺序放置到预先分配的SCSI缓冲区中,同时保持有序的数据传输。

2. Not require any major changes to the SCSI Architecture Model [SAM2] and SCSI command set standards.

2. 不需要对SCSI体系结构模型[SAM2]和SCSI命令集标准进行任何重大更改。

3. Utilize existing iSCSI infrastructure (sometimes referred to as "iSCSI ecosystem") including but not limited to MIB, bootstrapping, negotiation, naming and discovery, and security.

3. 利用现有的iSCSI基础架构(有时称为“iSCSI生态系统”),包括但不限于MIB、引导、协商、命名和发现以及安全性。

4. Require a session to operate in the Traditional iSCSI data transfer mode if iSER is not supported by either the initiator or the target (i.e., not require iSCSI Full Feature Phase interoperability between an end node operating in Traditional iSCSI mode, and an end node operating in iSER-assisted mode).

4. 如果启动器或目标不支持iSER,则需要会话以传统iSCSI数据传输模式运行(即,在以传统iSCSI模式运行的终端节点和以iSER辅助模式运行的终端节点之间不需要iSCSI全功能阶段互操作性)。

5. Allow initiator and target implementations to utilize generic RDMA-Capable Controllers such as RDMA-enabled Network Interface Controllers (RNICs), or to implement iSCSI and iSER in software (not require iSCSI- or iSER-specific assists in the RCaP implementation or RDMA-Capable Controller).

5. 允许启动器和目标实施使用支持RDMA的通用控制器,如支持RDMA的网络接口控制器(RNIC),或在软件中实施iSCSI和iSER(在RCaP实施或支持RDMA的控制器中不需要iSCSI或iSER特定的协助)。

6. Require full and only generic RCaP functionality at both the initiator and the target.

6. 在发起方和目标方都需要完整且仅通用的RCaP功能。

7. Implement a lightweight Datamover protocol for iSCSI with minimal state maintenance.

7. 使用最少的状态维护为iSCSI实施轻量级Datamover协议。

1.3. Protocol Overview
1.3. 协议概述

Consistent with the architectural goals stated in Section 2.2, the iSER protocol does not require changes in the iSCSI ecosystem or any related SCSI specifications. The iSER protocol defines the mapping of iSCSI PDUs to RCaP Messages in such a way that it is entirely feasible to realize iSCSI/iSER implementations that are based on generic RDMA-Capable Controllers. The iSER protocol layer requires minimal state maintenance to assist an iSCSI Full Feature Phase connection, besides being oblivious to the notion of an iSCSI session. The crucial protocol aspects of iSER may be summarized thus:

与第2.2节中所述的体系结构目标一致,iSER协议不需要更改iSCSI生态系统或任何相关的SCSI规范。iSER协议定义了iSCSI PDU到RCaP消息的映射,从而完全可以实现基于支持RDMA的通用控制器的iSCSI/iSER实现。iSER协议层除了不考虑iSCSI会话的概念外,还需要最少的状态维护来帮助iSCSI全功能阶段连接。iSER的关键协议方面可以总结如下:

1. iSER-assisted mode is negotiated during the iSCSI login for each session, and an entire iSCSI session can only operate in one mode (i.e., a connection in a session cannot operate in iSER-assisted mode if a different connection of the same session is already in Full Feature Phase in the Traditional iSCSI mode).

1. iSER辅助模式在每个会话的iSCSI登录期间协商,整个iSCSI会话只能在一种模式下运行(即,如果同一会话的不同连接在传统iSCSI模式下已处于全功能阶段,则会话中的连接无法在iSER辅助模式下运行)。

2. Once in iSER-assisted mode, all iSCSI interactions on that connection use RCaP Messages.

2. 一旦进入iSER辅助模式,该连接上的所有iSCSI交互都将使用RCaP消息。

3. A Send Message Type is used for carrying an iSCSI control-type PDU preceded by an iSER header. See Section 7.2 for more details on iSCSI control-type PDUs.

3. 发送消息类型用于承载前面带有iSER标头的iSCSI控制类型PDU。有关iSCSI控制类型PDU的更多详细信息,请参见第7.2节。

4. RDMA Write, RDMA Read Request, and RDMA Read Response Messages are used for carrying control and all data information associated with the iSCSI data-type PDUs. See Section 7.1 for more details on iSCSI data-type PDUs.

4. RDMA写入、RDMA读取请求和RDMA读取响应消息用于承载与iSCSI数据类型PDU相关的控制和所有数据信息。有关iSCSI数据类型PDU的更多详细信息,请参见第7.1节。

5. Target drives all data transfer (with the exception of iSCSI unsolicited data) for SCSI writes and SCSI reads, by issuing RDMA Read Requests and RDMA Writes, respectively.

5. 目标通过分别发出RDMA读取请求和RDMA写入,驱动SCSI写入和SCSI读取的所有数据传输(iSCSI未经请求的数据除外)。

6. RCaP is responsible for ensuring data integrity. (For example, iWARP includes a CRC-enhanced framing layer called Marker PDU Aligned Framing for TCP (MPA) on top of TCP; and for InfiniBand, the CRCs are included in the Reliable Connection mode). For this reason, iSCSI header and data digests are negotiated to "None" for iSCSI/iSER sessions.

6. RCaP负责确保数据完整性。(例如,iWARP包括一个CRC增强的成帧层,称为TCP(MPA)上的Marker PDU Aligned framing;对于InfiniBand,CRC包括在可靠连接模式中)。因此,iSCSI头和数据摘要对于iSCSI/iSER会话协商为“无”。

7. The iSCSI error recovery hierarchy defined in [RFC3720] is fully supported by iSER. (However, see Section 7.3.11 on the handling of SNACK Request PDUs.)

7. iSER完全支持[RFC3720]中定义的iSCSI错误恢复层次结构。(但是,请参见第7.3.11节关于零食请求PDU的处理。)

8. iSER requires no changes to iSCSI authentication, security, and text mode negotiation mechanisms.

8. iSER不需要更改iSCSI身份验证、安全性和文本模式协商机制。

Note that Traditional iSCSI implementations may have to be adapted to employ iSER. It is expected that the adaptation when required is likely to be centered around the upper layer interface requirements of iSER (Section 3).

请注意,传统的iSCSI实施可能必须进行调整以使用iSER。预计需要时的适配可能以iSER的上层接口需求为中心(第3节)。

1.4. RDMA Services and iSER
1.4. RDMA服务和iSER

iSER is designed to work with software and/or hardware protocol stacks providing the protocol services defined in RCaP documents such as [RDMAP], [IB], etc. The following subsections describe the key protocol elements of RCaP services that iSER relies on.

iSER设计用于使用软件和/或硬件协议栈,提供RCaP文档(如[RDMAP]、[IB]等)中定义的协议服务。以下小节描述iSER所依赖的RCaP服务的关键协议元素。

1.4.1. STag
1.4.1. 雄鹿

A Steering Tag (STag) is the identifier of an I/O Buffer unique to an RDMA-Capable Controller that the iSER layer Advertises to the remote iSCSI/iSER node in order to complete a SCSI I/O.

转向标签(STag)是支持RDMA的控制器特有的I/O缓冲区的标识符,iSER层向远程iSCSI/iSER节点播发该控制器,以完成SCSI I/O。

In iSER, Advertisement is the act of informing the target by the initiator that an I/O Buffer is available at the initiator for RDMA Read or RDMA Write access by the target. The initiator Advertises the I/O Buffer by including the STag in the header of an iSER Message containing the SCSI Command PDU to the target. The base Tagged Offset is not explicitly specified, but the target must always assume it as zero. The buffer length is as specified in the SCSI Command PDU.

在iSER中,播发是由发起方通知目标方在发起方有I/O缓冲区可供目标方进行RDMA读或RDMA写访问的行为。启动器通过在包含SCSI命令PDU的iSER消息头中包含STag向目标播发I/O缓冲区。未明确指定“基准标记偏移”,但目标必须始终假定它为零。缓冲区长度在SCSI命令PDU中指定。

The iSER layer at the initiator Advertises the STag for the I/O Buffer of each SCSI I/O to the iSER layer at the target in the iSER header of the Send with Solicited Event (SendSE) Message containing the SCSI Command PDU, unless the I/O can be completely satisfied by unsolicited data alone.

启动器处的iSER层在包含SCSI命令PDU的请求发送事件(SendSE)消息的iSER头中将每个SCSI I/O的I/O缓冲区的STag播发到目标处的iSER层,除非仅通过未经请求的数据即可完全满足I/O。

The iSER layer at the target provides the STag for the I/O Buffer that is the Data Sink of an RDMA Read Operation (Section 2.4.4) to the RCaP layer on the initiator node -- i.e., this is completely transparent to the iSER layer at the initiator.

目标端的iSER层向发起方节点上的RCaP层提供作为RDMA读取操作(第2.4.4节)数据接收器的I/O缓冲区的STag——即,这对发起方端的iSER层是完全透明的。

The iSER protocol is defined so that the Advertised STag is automatically invalidated upon a normal completion of the associated task. This automatic invalidation is realized via the Send with

iSER协议的定义使得在相关任务正常完成时,播发的STag自动失效。这种自动失效是通过发送来实现的

Solicited Event and Invalidate (SendInvSE) Message carrying the SCSI Response PDU. There are two exceptions to this automatic invalidation -- bidirectional commands, and abnormal completion of a command. The iSER layer at the initiator is required to explicitly invalidate the STag in these cases, in addition to sanity checking the automatic invalidation even when that does happen.

携带SCSI响应PDU的请求事件和失效(SendInvSE)消息。这种自动失效有两个例外——双向命令和命令异常完成。在这些情况下,除了对自动失效进行健全性检查之外,还需要启动器处的iSER层显式地使STag失效。

1.4.2. Send
1.4.2. 邮寄

Send is the RDMA Operation that is not addressed to an Advertised buffer by the sending side, and thus uses Untagged buffers on the receiving side.

发送是RDMA操作,发送端不将其发送到播发缓冲区,因此在接收端使用未标记的缓冲区。

The iSER layer at the initiator uses the Send Operation to transmit any iSCSI control-type PDU to the target. As an example, the initiator uses Send Operations to transfer iSER Messages containing SCSI Command PDUs to the iSER layer at the target.

启动器处的iSER层使用发送操作将任何iSCSI控制类型的PDU传输到目标。例如,启动器使用发送操作将包含SCSI命令PDU的iSER消息传输到目标的iSER层。

An iSER layer at the target uses the Send Operation to transmit any iSCSI control-type PDU to the initiator. As an example, the target uses Send Operations to transfer iSER Messages containing SCSI Response PDUs to the iSER layer at the initiator.

目标位置的iSER层使用发送操作将任何iSCSI控制类型的PDU传输到启动器。例如,目标使用发送操作将包含SCSI响应PDU的iSER消息传输到启动器的iSER层。

1.4.3. RDMA Write
1.4.3. RDMA写入

RDMA Write is the RDMA Operation that is used to place data into an Advertised buffer on the receiving side. The sending side addresses the Message using an STag and a Tagged Offset that are valid on the Data Sink.

RDMA写入是RDMA操作,用于将数据放入接收端的播发缓冲区。发送端使用STag和在数据接收器上有效的标记偏移量对消息进行寻址。

The iSER layer at the target uses the RDMA Write Operation to transfer the contents of a local I/O Buffer to an Advertised I/O Buffer at the initiator. The iSER layer at the target uses the RDMA Write to transfer whole or part of the data required to complete a SCSI read command.

目标端的iSER层使用RDMA写操作将本地I/O缓冲区的内容传输到发起端的播发I/O缓冲区。目标服务器的iSER层使用RDMA写入来传输完成SCSI读取命令所需的全部或部分数据。

The iSER layer at the initiator does not employ RDMA Writes.

启动器处的iSER层不采用RDMA写入。

1.4.4. RDMA Read
1.4.4. RDMA读取

RDMA Read is the RDMA Operation that is used to retrieve data from an Advertised buffer on a remote node. The sending side of the RDMA Read Request addresses the Message using an STag and a Tagged Offset that are valid on the Data Source in addition to providing a valid local STag and Tagged Offset that identify the Data Sink.

RDMA Read是用于从远程节点上的播发缓冲区检索数据的RDMA操作。RDMA读取请求的发送端使用在数据源上有效的STag和标记偏移量对消息进行寻址,此外还提供识别数据接收器的有效本地STag和标记偏移量。

The iSER layer at the target uses the RDMA Read Operation to transfer the contents of an Advertised I/O Buffer at the initiator to a local

目标服务器上的iSER层使用RDMA读取操作将启动器上公布的I/O缓冲区的内容传输到本地服务器

I/O Buffer at the target. The iSER layer at the target uses the RDMA Read to fetch whole or part of the data required to complete a SCSI write command.

目标上的I/O缓冲区。目标的iSER层使用RDMA Read获取完成SCSI写入命令所需的全部或部分数据。

The iSER layer at the initiator does not employ RDMA Reads.

启动器处的iSER层不采用RDMA读取。

1.5. SCSI Read Overview
1.5. SCSI读取概述

The iSER layer at the initiator receives the SCSI Command PDU from the iSCSI layer. The iSER layer at the initiator generates an STag for the I/O Buffer of the SCSI Read and Advertises the buffer by including the STag as part of the iSER header for the PDU. The iSER Message is transferred to the target using a SendSE Message.

启动器处的iSER层从iSCSI层接收SCSI命令PDU。启动器处的iSER层为SCSI读取的I/O缓冲区生成STag,并通过将STag作为PDU的iSER头的一部分来播发缓冲区。iSER消息使用SendSE消息传输到目标。

The iSER layer at the target uses one or more RDMA Writes to transfer the data required to complete the SCSI Read.

目标的iSER层使用一个或多个RDMA写入来传输完成SCSI读取所需的数据。

The iSER layer at the target uses a SendInvSE Message to transfer the SCSI Response PDU back to the iSER layer at the initiator. The iSER layer at the initiator notifies the iSCSI layer of the availability of the SCSI Response PDU.

目标端的iSER层使用SendInvSE消息将SCSI响应PDU传输回启动器端的iSER层。启动器处的iSER层通知iSCSI层SCSI响应PDU的可用性。

1.6. SCSI Write Overview
1.6. SCSI写入概述

The iSER layer at the initiator receives the SCSI Command PDU from the iSCSI layer. If solicited data transfer is involved, the iSER layer at the initiator generates an STag for the I/O Buffer of the SCSI Write and Advertises the buffer by including the STag as part of the iSER header for the PDU. The iSER Message is transferred to the target using a SendSE Message.

启动器处的iSER层从iSCSI层接收SCSI命令PDU。如果涉及请求的数据传输,则启动器处的iSER层为SCSI写入的I/O缓冲区生成STag,并通过将STag作为PDU的iSER头的一部分来播发缓冲区。iSER消息使用SendSE消息传输到目标。

The iSER layer at the initiator may optionally send one or more non-immediate unsolicited data PDUs to the target using Send Message Types.

启动器处的iSER层可以使用发送消息类型选择性地向目标发送一个或多个非即时非请求数据PDU。

If solicited data transfer is involved, the iSER layer at the target uses one or more RDMA Reads to transfer the data required to complete the SCSI Write.

如果涉及请求的数据传输,目标的iSER层将使用一个或多个RDMA读取来传输完成SCSI写入所需的数据。

The iSER layer at the target uses a SendInvSE Message to transfer the SCSI Response PDU back to the iSER layer at the initiator. The iSER layer at the initiator notifies the iSCSI layer of the availability of the SCSI Response PDU.

目标端的iSER层使用SendInvSE消息将SCSI响应PDU传输回启动器端的iSER层。启动器处的iSER层通知iSCSI层SCSI响应PDU的可用性。

1.7. iSCSI/iSER Layering
1.7. iSCSI/iSER分层

iSCSI Extensions for RDMA (iSER) is layered between the iSCSI layer and the RCaP layer. Note that the RCaP layer may be composed of one

RDMA的iSCSI扩展(iSER)分层在iSCSI层和RCaP层之间。注意,RCaP层可以由一个

or more distinct protocol layers depending on the specifics of the RCaP. Figure 1 shows an example of the relationship between SCSI, iSCSI, iSER, and the different RCaP layers. For TCP, the RCaP is iWARP. For InfiniBand, the RCaP is the Reliable Connected Transport Service. Note that the iSCSI layer as described here supports the RDMA Extensions as used in iSER.

或更多不同的协议层,具体取决于RCaP的具体情况。图1显示了SCSI、iSCSI、iSER和不同RCaP层之间关系的示例。对于TCP,RCaP是iWARP。对于InfiniBand,RCaP是可靠的连接传输服务。请注意,此处描述的iSCSI层支持iSER中使用的RDMA扩展。

                 +-------------------------------------+
                 |              SCSI                   |
                 +-------------------------------------+
                 |              iSCSI                  |
      DI ------> +-------------------------------------+
                 |              iSER                   |
                 +---------+--------------+------------+
                 |  RDMAP  |              |            |
                 +---------+  InfiniBand  |            |
                 |   DDP   |   Reliable   |   Other    |
                 +---------+  Connected   |   RDMA-    |
                 |   MPA   |  Transport   |  Capable   |
                 +---------+   Service    |  Protocol  |
                 |   TCP   |              |            |
                 +---------+--------------+------------+
                 |         |  InfiniBand  |   Other    |
                 |    IP   |   Network    |  Network   |
                 |         |    Layer     |   Layer    |
                 +---------+--------------+------------+
        
                 +-------------------------------------+
                 |              SCSI                   |
                 +-------------------------------------+
                 |              iSCSI                  |
      DI ------> +-------------------------------------+
                 |              iSER                   |
                 +---------+--------------+------------+
                 |  RDMAP  |              |            |
                 +---------+  InfiniBand  |            |
                 |   DDP   |   Reliable   |   Other    |
                 +---------+  Connected   |   RDMA-    |
                 |   MPA   |  Transport   |  Capable   |
                 +---------+   Service    |  Protocol  |
                 |   TCP   |              |            |
                 +---------+--------------+------------+
                 |         |  InfiniBand  |   Other    |
                 |    IP   |   Network    |  Network   |
                 |         |    Layer     |   Layer    |
                 +---------+--------------+------------+
        

Figure 1. Example of iSCSI/iSER Layering in Full Feature Phase

图1。完整功能阶段的iSCSI/iSER分层示例

2. Definitions and Acronyms
2. 定义和首字母缩略词
2.1. Definitions
2.1. 定义

Advertisement (Advertised, Advertise, Advertisements, Advertises) - The act of informing a remote iSER layer that a local node's buffer is available to it. A Node makes a buffer available for incoming RDMA Read Request Message or incoming RDMA Write Message access by informing the remote iSER layer of the Tagged Buffer identifiers (STag, TO, and buffer length). Note that this Advertisement of Tagged Buffer information is the responsibility of the iSER layer on either end and is not defined by the RDMA-Capable Protocol. A typical method would be for the iSER layer to embed the Tagged Buffer's STag, TO, and buffer length in a Send Message destined for the remote iSER layer.

广告(广告、广告、广告、广告)-通知远程iSER层本地节点的缓冲区对其可用的行为。节点通过通知远程iSER层标记的缓冲区标识符(STag、TO和缓冲区长度),使缓冲区可用于传入RDMA读取请求消息或传入RDMA写入消息访问。请注意,标记缓冲区信息的发布是两端iSER层的责任,不由支持RDMA的协议定义。典型的方法是iSER层将标记缓冲区的STag、to和缓冲区长度嵌入到发送到远程iSER层的发送消息中。

Completion (Completed, Complete, Completes) - Completion is defined as the process by the RDMA-Capable Protocol layer to inform the

完成(Completed,Complete,Completed)-完成被定义为由支持RDMA的协议层通知

iSER layer, that a particular RDMA Operation has performed all functions specified for the RDMA Operation.

iSER层,即特定RDMA操作已执行为RDMA操作指定的所有功能。

Connection - A connection is a logical circuit between the initiator and the target, e.g., a TCP connection. Communication between the initiator and the target occurs over one or more connections. The connections carry control messages, SCSI commands, parameters, and data within iSCSI Protocol Data Units (iSCSI PDUs).

连接-连接是启动器和目标之间的逻辑电路,例如TCP连接。启动器和目标之间的通信通过一个或多个连接进行。这些连接在iSCSI协议数据单元(iSCSI PDU)中承载控制消息、SCSI命令、参数和数据。

Connection Handle - An information element that identifies the particular iSCSI connection and is unique for a given iSCSI-iSER pair. Every invocation of an Operational Primitive is qualified with the Connection Handle.

连接句柄—标识特定iSCSI连接的信息元素,对于给定的iSCSI iSER对来说是唯一的。操作原语的每次调用都使用连接句柄限定。

Data Sink - The peer receiving a data payload. Note that the Data Sink can be required to both send and receive RCaP Messages to transfer a data payload.

数据接收器-接收数据有效负载的对等方。请注意,可以要求数据接收器发送和接收RCaP消息以传输数据有效负载。

Data Source - The peer sending a data payload. Note that the Data Source can be required to both send and receive RCaP Messages to transfer a data payload.

数据源-发送数据有效负载的对等方。请注意,可以要求数据源发送和接收RCaP消息以传输数据有效负载。

Datamover Interface (DI) - The interface between the iSCSI layer and the Datamover layer as described in [DA].

Datamover接口(DI)-iSCSI层和Datamover层之间的接口,如[DA]中所述。

Datamover Layer - A layer that is directly below the iSCSI layer and above the underlying transport layers. This layer exposes and uses a set of transport independent Operational Primitives for the communication between the iSCSI layer and itself. The Datamover layer, operating in conjunction with the transport layers, moves the control and data information on the iSCSI connection. In this specification, the iSER layer is the Datamover layer.

Datamover层—位于iSCSI层正下方和底层传输层之上的层。该层公开并使用一组独立于传输的操作原语,用于iSCSI层与自身之间的通信。Datamover层与传输层一起工作,移动iSCSI连接上的控制和数据信息。在本规范中,iSER层是Datamover层。

Datamover Protocol - A Datamover protocol is the wire-protocol that is defined to realize the Datamover layer functionality. In this specification, the iSER protocol is the Datamover protocol.

Datamover协议—Datamover协议是为实现Datamover层功能而定义的有线协议。在本规范中,iSER协议是Datamover协议。

Event - An indication provided by the RDMA-Capable Protocol layer to the iSER layer to indicate a Completion or other condition requiring immediate attention.

事件-支持RDMA的协议层向iSER层提供的指示,以指示完成或其他需要立即注意的情况。

Inbound RDMA Read Queue Depth (IRD) - The maximum number of incoming outstanding RDMA Read Requests that the RDMA-Capable Controller can handle on a particular RCaP Stream at the Data Source. For some RDMA-Capable Protocol layers, the term "IRD" may be known by a different name. For example, for InfiniBand, the equivalent for IRD is the Responder Resources.

Inbound RDMA Read Queue Depth(IRD)—支持RDMA的控制器可以在数据源的特定RCaP流上处理的最大未完成RDMA读取请求数。对于一些支持RDMA的协议层,术语“IRD”可以用不同的名称来表示。例如,对于InfiniBand,IRD的等价物是响应者资源。

Invalidate STag - A mechanism used to prevent the Remote Peer from reusing a previous explicitly Advertised STag, until the iSER layer at the local node makes it available through a subsequent explicit Advertisement.

Invalidate STag-一种用于防止远程对等方重用先前显式公布的STag的机制,直到本地节点的iSER层通过后续显式公布使其可用。

I/O Buffer - A buffer that is used in a SCSI Read or Write operation so SCSI data may be sent from or received into that buffer.

I/O缓冲区—在SCSI读写操作中使用的缓冲区,以便SCSI数据可以从该缓冲区发送或接收。

iSCSI - The iSCSI protocol as defined in [RFC3720] is a mapping of the SCSI Architecture Model of SAM-2 over TCP.

iSCSI—在[RFC3720]中定义的iSCSI协议是SAM-2的SCSI体系结构模型在TCP上的映射。

iSCSI control-type PDU - Any iSCSI PDU that is not an iSCSI data-type PDU and also not a SCSI Data-out PDU carrying solicited data is defined as an iSCSI control-type PDU. Specifically, it is to be noted that SCSI Data-out PDUs for unsolicited data are defined as iSCSI control-type PDUs.

iSCSI控制类型PDU—任何不是iSCSI数据类型PDU,也不是承载请求数据的SCSI数据输出PDU的iSCSI PDU都定义为iSCSI控制类型PDU。具体而言,需要注意的是,用于非请求数据的SCSI数据输出PDU被定义为iSCSI控制类型PDU。

iSCSI data-type PDU - An iSCSI data-type PDU is defined as an iSCSI PDU that causes data transfer, transparent to the remote iSCSI layer, to take place between the peer iSCSI nodes on a Full Feature Phase iSCSI connection. An iSCSI data-type PDU, when requested for transmission by the sender iSCSI layer, results in the associated data transfer without the participation of the remote iSCSI layer, i.e. the PDU itself is not delivered as-is to the remote iSCSI layer. The following iSCSI PDUs constitute the set of iSCSI data-type PDUs - SCSI Data-In PDU and R2T PDU.

iSCSI数据类型PDU—iSCSI数据类型PDU定义为iSCSI PDU,它使数据传输(对远程iSCSI层透明)在全功能阶段iSCSI连接上的对等iSCSI节点之间进行。当发送方iSCSI层请求传输iSCSI数据类型PDU时,会导致相关数据传输而无需远程iSCSI层参与,即PDU本身不会按原样传送到远程iSCSI层。以下iSCSI PDU构成了一组iSCSI数据类型PDU—PDU和R2T PDU中的SCSI数据。

iSCSI Layer - A layer in the protocol stack implementation within an end node that implements the iSCSI protocol and interfaces with the iSER layer via the Datamover Interface.

iSCSI层—终端节点内协议栈实现中的一层,用于实现iSCSI协议并通过Datamover接口与iSER层接口。

iSCSI PDU (iSCSI Protocol Data Unit) - The iSCSI layer at the initiator and the iSCSI layer at the target divide their communications into messages. The term "iSCSI protocol data unit" (iSCSI PDU) is used for these messages.

iSCSI PDU(iSCSI协议数据单元)—启动器的iSCSI层和目标的iSCSI层将其通信划分为消息。术语“iSCSI协议数据单元”(iSCSI PDU)用于这些消息。

iSCSI/iSER Connection - An iSER-assisted iSCSI connection.

iSCSI/iSER连接—iSER辅助的iSCSI连接。

iSCSI/iSER Session - An iSER-assisted iSCSI session.

iSCSI/iSER会话—iSER辅助的iSCSI会话。

iSCSI-iSER Pair - The iSCSI layer and the underlying iSER layer.

iSCSI iSER对—iSCSI层和底层iSER层。

iSER - iSCSI Extensions for RDMA, the protocol defined in this document.

iSER-用于RDMA的iSCSI扩展,本文档中定义的协议。

iSER-assisted - A term generally used to describe the operation of iSCSI when the iSER functionality is also enabled below the iSCSI layer for the specific iSCSI/iSER connection in question.

iSER辅助—一个术语,通常用于描述在特定iSCSI/iSER连接的iSCSI层下启用iSER功能时的iSCSI操作。

iSER-IRD - This variable represents the maximum number of incoming outstanding RDMA Read Requests that the iSER layer at the initiator declares on a particular RCaP Stream.

iSER IRD-此变量表示启动器的iSER层在特定RCaP流上声明的最大传入未完成RDMA读取请求数。

iSER-ORD - This variable represents the maximum number of outstanding RDMA Read Requests that the iSER layer can initiate on a particular RCaP Stream. This variable is maintained only by the iSER layer at the target.

iSER ORD-此变量表示iSER层可以在特定RCaP流上启动的未完成RDMA读取请求的最大数量。此变量仅由目标的iSER层维护。

iSER Layer - The layer that implements the iSCSI Extensions for RDMA (iSER) protocol.

iSER层—实现RDMA(iSER)协议的iSCSI扩展的层。

iWARP - A suite of wire protocols comprising of [RDMAP], [DDP], and [MPA] when layered above [TCP]. [RDMAP] and [DDP] may be layered above SCTP or other transport protocols.

iWARP—一套有线协议,在[TCP]之上分层时由[RDMAP]、[DDP]和[MPA]组成。[RDMAP]和[DDP]可以分层在SCTP或其他传输协议之上。

Local Mapping - A task state record maintained by the iSER layer that associates the Initiator Task Tag to the local STag(s). The specifics of the record structure are implementation dependent.

本地映射—iSER层维护的任务状态记录,它将启动器任务标记与本地STag关联。记录结构的细节取决于实现。

Local Peer - The implementation of the RDMA-Capable Protocol on the local end of the connection. Used to refer to the local entity when describing protocol exchanges or other interactions between two Nodes.

本地对等-在连接的本地端实现支持RDMA的协议。在描述两个节点之间的协议交换或其他交互时,用于引用本地实体。

Node - A computing device attached to one or more links of a network. A Node in this context does not refer to a specific application or protocol instantiation running on the computer. A Node may consist of one or more RDMA-Capable Controllers installed in a host computer.

节点-连接到网络的一个或多个链路的计算设备。此上下文中的节点不引用计算机上运行的特定应用程序或协议实例化。节点可以由安装在主机中的一个或多个支持RDMA的控制器组成。

Operational Primitive - An Operational Primitive is an abstract functional interface procedure that requests that another layer perform a specific action on the requestor's behalf or notifies the other layer of some event. The Datamover Interface between an iSCSI layer and a Datamover layer within an iSCSI end node uses a set of Operational Primitives to define the functional interface between the two layers. Note that not every invocation of an Operational Primitive may elicit a response from the requested layer. A full discussion of the Operational Primitive types and request-response semantics available to iSCSI and iSER can be found in [DA].

操作原语-操作原语是一个抽象的功能接口过程,它请求另一层代表请求者执行特定操作,或通知另一层某个事件。iSCSI层和iSCSI终端节点内的Datamover层之间的Datamover接口使用一组操作原语定义两层之间的功能接口。请注意,并不是每次调用操作原语都会从请求的层引发响应。有关iSCSI和iSER可用的操作原语类型和请求-响应语义的完整讨论,请参见[DA]。

Outbound RDMA Read Queue Depth (ORD) - The maximum number of outstanding RDMA Read Requests that the RDMA-Capable Controller can initiate on a particular RCaP Stream at the Data Sink. For

Outbound RDMA Read Queue Depth(ORD)-支持RDMA的控制器可以在数据接收器的特定RCaP流上启动的未完成RDMA读取请求的最大数量。对于

some RDMA-Capable Protocol layer, the term "ORD" may be known by a different name. For example, for InfiniBand, the equivalent for ORD is the Initiator Depth.

在一些支持RDMA的协议层中,术语“ORD”可以用不同的名称来表示。例如,对于InfiniBand,ORD的等效值是启动器深度。

Phase-Collapse - Refers to the optimization in iSCSI where the SCSI status is transferred along with the final SCSI Data-in PDU from a target. See Section 3.2 in [RFC3720].

阶段崩溃-指iSCSI中的优化,其中SCSI状态与PDU中来自目标的最终SCSI数据一起传输。参见[RFC3720]中的第3.2节。

RCaP Message - One or more packets of the network layer comprising a single RDMA Operation or a part of an RDMA Read Operation of the RDMA-Capable Protocol. For iWARP, an RCaP Message is known as an RDMAP Message.

RCaP消息-网络层的一个或多个数据包,包括单个RDMA操作或支持RDMA协议的RDMA读取操作的一部分。对于iWARP,RCaP消息称为RDMAP消息。

RCaP Stream - A single bidirectional association between the peer RDMA-Capable Protocol layers on two Nodes over a single transport-level stream. For iWARP, an RCaP Stream is known as an RDMAP Stream, and the association is created when the connection transitions to iSER-assisted mode following a successful Login Phase during which iSER support is negotiated.

RCaP流-在单个传输级流上,两个节点上支持RDMA的对等协议层之间的单个双向关联。对于iWARP,RCaP流被称为RDMAP流,当连接在成功登录阶段(在此期间协商iSER支持)后转换到iSER辅助模式时,将创建关联。

RDMA-Capable Protocol (RCaP) - The protocol or protocol suite that provides a reliable RDMA transport functionality, e.g., iWARP, InfiniBand, etc.

支持RDMA的协议(RCaP)-提供可靠RDMA传输功能的协议或协议套件,例如iWARP、InfiniBand等。

RDMA-Capable Controller - A network I/O adapter or embedded controller with RDMA functionality. For example, for iWARP, this could be an RNIC, and for InfiniBand, this could be a HCA (Host Channel Adapter) or TCA (Target Channel Adapter).

支持RDMA的控制器-具有RDMA功能的网络I/O适配器或嵌入式控制器。例如,对于iWARP,这可能是一个RNIC,对于InfiniBand,这可能是一个HCA(主机通道适配器)或TCA(目标通道适配器)。

RDMA-enabled Network Interface Controller (RNIC) - A network I/O adapter or embedded controller with iWARP functionality.

支持RDMA的网络接口控制器(RNIC)-具有iWARP功能的网络I/O适配器或嵌入式控制器。

RDMA Operation - A sequence of RCaP Messages, including control Messages, to transfer data from a Data Source to a Data Sink. The following RDMA Operations are defined - RDMA Write Operation, RDMA Read Operation, Send Operation, Send with Invalidate Operation, Send with Solicited Event Operation, Send with Solicited Event and Invalidate Operation, and Terminate Operation.

RDMA操作-一系列RCaP消息,包括控制消息,用于将数据从数据源传输到数据接收器。定义了以下RDMA操作—RDMA写入操作、RDMA读取操作、发送操作、发送时使用无效操作、发送时使用请求的事件操作、发送时使用请求的事件和无效操作,以及终止操作。

RDMA Protocol (RDMAP) - A wire protocol that supports RDMA Operations to transfer ULP data between a Local Peer and the Remote Peer as described in [RDMAP].

RDMA协议(RDMAP)-一种支持RDMA操作的有线协议,用于在本地对等方和远程对等方之间传输ULP数据,如[RDMAP]中所述。

RDMA Read Operation - An RDMA Operation used by the Data Sink to transfer the contents of a Data Source buffer from the Remote Peer to a Data Sink buffer at the Local Peer. An RDMA Read operation consists of a single RDMA Read Request Message and a single RDMA Read Response Message.

RDMA读取操作—数据接收器使用的一种RDMA操作,用于将数据源缓冲区的内容从远程对等方传输到本地对等方的数据接收器缓冲区。RDMA读取操作由单个RDMA读取请求消息和单个RDMA读取响应消息组成。

RDMA Read Request - An RCaP Message used by the Data Sink to request that the Data Source transfer the contents of a buffer. The RDMA Read Request Message describes both the Data Source and the Data Sink buffers.

RDMA Read Request—数据接收器用于请求数据源传输缓冲区内容的RCaP消息。RDMA读取请求消息描述数据源和数据接收器缓冲区。

RDMA Read Response - An RCaP Message used by the Data Source to transfer the contents of a buffer to the Data Sink, in response to an RDMA Read Request. The RDMA Read Response Message only describes the Data Sink buffer.

RDMA Read Response(RDMA读取响应)—数据源用于响应RDMA读取请求,将缓冲区内容传输到数据接收器的RCaP消息。RDMA读取响应消息仅描述数据接收器缓冲区。

RDMA Write Operation - An RDMA Operation used by the Data Source to transfer the contents of a Data Source buffer from the Local Peer to a Data Sink buffer at the Remote Peer. The RDMA Write Message only describes the Data Sink buffer.

RDMA写入操作—数据源用于将数据源缓冲区的内容从本地对等方传输到远程对等方的数据接收器缓冲区的RDMA操作。RDMA写入消息仅描述数据接收器缓冲区。

Remote Direct Memory Access (RDMA) - A method of accessing memory on a remote system in which the local system specifies the remote location of the data to be transferred. Employing an RDMA-Capable Controller in the remote system allows the access to take place without interrupting the processing of the CPU(s) on the system.

远程直接内存访问(RDMA)—一种访问远程系统内存的方法,其中本地系统指定要传输的数据的远程位置。在远程系统中使用支持RDMA的控制器允许在不中断系统上CPU处理的情况下进行访问。

Remote Mapping - A task state record maintained by the iSER layer that associates the Initiator Task Tag to the Advertised STag(s). The specifics of the record structure are implementation dependent.

远程映射—由iSER层维护的任务状态记录,它将启动器任务标记与播发的STag相关联。记录结构的细节取决于实现。

Remote Peer - The implementation of the RDMA-Capable Protocol on the opposite end of the connection. Used to refer to the remote entity when describing protocol exchanges or other interactions between two Nodes.

远程对等-在连接的另一端实现支持RDMA的协议。在描述两个节点之间的协议交换或其他交互时,用于指代远程实体。

SCSI Layer - This layer builds/receives SCSI CDBs (Command Descriptor Blocks) and sends/receives them with the remaining command execute [SAM2] parameters to/from the iSCSI layer.

SCSI层—该层构建/接收SCSI CDB(命令描述符块),并将其与剩余的命令执行[SAM2]参数一起发送/接收到iSCSI层。

Send - An RDMA Operation that transfers the contents of a Buffer from the Local Peer to a Buffer at the Remote Peer.

发送-一种RDMA操作,将缓冲区的内容从本地对等方传输到远程对等方的缓冲区。

Send Message Type - A Send Message, Send with Invalidate Message, Send with Solicited Event Message, or Send with Solicited Event and Invalidate Message.

发送消息类型-发送消息、使用无效消息发送、使用请求的事件消息发送或使用请求的事件和无效消息发送。

SendInvSE Message - A Send with Solicited Event and Invalidate Message.

SendInvSE消息-包含请求事件和无效消息的发送。

SendSE Message - A Send with Solicited Event Message.

SendSE Message-发送请求的事件消息。

Sequence Number (SN) - DataSN for a SCSI Data-in PDU and R2TSN for an R2T PDU. The semantics for both types of sequence numbers are as defined in [RFC3720].

序列号(SN)-PDU中SCSI数据的DataSN和R2T PDU的R2TSN。这两种序列号的语义如[RFC3720]中所定义。

Session, iSCSI Session - The group of connections that link an initiator SCSI port with a target SCSI port form an iSCSI session (equivalent to a SCSI I-T nexus). Connections can be added to and removed from a session even while the I-T nexus is intact. Across all connections within a session, an initiator sees one and the same target.

会话,iSCSI会话—将启动器SCSI端口与目标SCSI端口链接起来形成iSCSI会话的连接组(相当于SCSI I-T nexus)。即使I-T连接完好无损,也可以在会话中添加和删除连接。在会话中的所有连接中,启动器都会看到同一个目标。

Solicited Event (SE) - A facility by which an RDMA Operation sender may cause an Event to be generated at the recipient, if the recipient is configured to generate such an Event, when a Send with Solicited Event or Send with Solicited Event and Invalidate Message is received.

请求事件(SE)-当接收到请求事件发送或请求事件发送并失效消息时,如果收件人被配置为生成此类事件,RDMA操作发送方可通过此功能在收件人处生成事件。

Steering Tag (STag) - An identifier of a Tagged Buffer on a Node (Local or Remote) as defined in [RDMAP] and [DDP]. For other RDMA-Capable Protocols, the Steering Tag may be known by different names but will be herein referred to as STags. For example, for InfiniBand, a Remote STag is known as an R-Key, and a local STag is known as an L-Key, and both will be considered STags.

转向标签(STag)-[RDMAP]和[DDP]中定义的节点(本地或远程)上标记缓冲区的标识符。对于其他支持RDMA的协议,转向标签可以用不同的名称来表示,但在本文中称为STAG。例如,对于InfiniBand,远程STag称为R密钥,本地STag称为L密钥,两者都将被视为STag。

Tagged Buffer - A buffer that is explicitly Advertised to the iSER layer at the remote node through the exchange of an STag, Tagged Offset, and length.

标记的缓冲区-通过交换STag、标记的偏移量和长度,显式播发到远程节点的iSER层的缓冲区。

Tagged Offset (TO) - The offset within a Tagged Buffer.

标记的偏移量(到)-标记的缓冲区内的偏移量。

Traditional iSCSI - Refers to the iSCSI protocol as defined in [RFC3720] (i.e. without the iSER enhancements).

传统iSCSI—指[RFC3720]中定义的iSCSI协议(即,没有iSER增强)。

Untagged Buffer - A buffer that is not explicitly Advertised to the iSER layer at the remode node.

未标记缓冲区-未在remode节点显式播发到iSER层的缓冲区。

2.2. Acronyms
2.2. 缩略词
      Acronym        Definition
      --------------------------------------------------------------
        
      Acronym        Definition
      --------------------------------------------------------------
        

AHS Additional Header Segment

AHS附加头段

BHS Basic Header Segment

基本头段

CO Connection Only

仅限联合连接

CRC Cyclic Redundancy Check

循环冗余校验

DDP Direct Data Placement Protocol

直接数据放置协议

DI Datamover Interface

DI数据移动器接口

HCA Host Channel Adapter

主机通道适配器

IANA Internet Assigned Numbers Authority

IANA互联网分配号码管理局

IB InfiniBand

IB InfiniBand

IETF Internet Engineering Task Force

因特网工程任务组

I/O Input - Output

I/O输入-输出

IO Initialize Only

仅初始化IO

IP Internet Protocol

网际协议

IPoIB IP over InfiniBand

InfiniBand上的IPoIB IP

IPsec Internet Protocol Security

IPsec因特网协议安全

iSER iSCSI Extensions for RDMA

用于RDMA的iSER iSCSI扩展

ITT Initiator Task Tag

ITT启动器任务标记

LO Leading Only

LO仅领先

MPA Marker PDU Aligned Framing for TCP

TCP的MPA标记PDU对齐帧

NOP No Operation

没有手术

NSG Next Stage (during the iSCSI Login Phase)

NSG下一阶段(在iSCSI登录阶段)

OS Operating System

操作系统

PDU Protocol Data Unit

协议数据单元

R2T Ready To Transfer

R2T准备转移

R2TSN Ready To Transfer Sequence Number

R2TSN准备传输序列号

RDMA Remote Direct Memory Access

远程直接内存访问

RDMAP Remote Direct Memory Access Protocol

RDMAP远程直接内存访问协议

RFC Request For Comments

征求意见

RNIC RDMA-enabled Network Interface Controller

RNIC支持RDMA的网络接口控制器

SAM2 SCSI Architecture Model - 2

SAM2 SCSI体系结构模型-2

SCSI Small Computer Systems Interface

小型计算机系统接口

SNACK Selective Negative Acknowledgment - also Sequence Number Acknowledgement for data

SNACK选择性否定确认-也是数据的序列号确认

STag Steering Tag

STag转向标签

SW Session Wide

软件会话范围

TCA Target Channel Adapter

目标信道适配器

TCP Transmission Control Protocol

TCP传输控制协议

TMF Task Management Function

任务管理功能

TTT Target Transfer Tag

目标转移标签

TO Tagged Offset

标记偏移量

ULP Upper Level Protocol

ULP上层协议

2.3. Conventions
2.3. 习俗

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。

3. Upper Layer Interface Requirements
3. 上层接口要求

This section discusses the upper layer interface requirements in the form of an abstract model of the required interactions between the iSCSI layer and the iSER layer. The abstract model used here is derived from the architectural model described in [DA]. [DA] also provides a functional overview of the interactions between the iSCSI layer and the Datamover layer as intended by the Datamover Architecture.

本节以iSCSI层和iSER层之间所需交互的抽象模型的形式讨论上层接口需求。此处使用的抽象模型源自[DA]中描述的体系结构模型。[DA]还提供了数据移动器体系结构预期的iSCSI层和数据移动器层之间交互的功能概述。

The interface requirements are specified by Operational Primitives. An Operational Primitive is an abstract functional interface procedure between the iSCSI layer and the iSER layer that requests one layer to perform a specific action on behalf of the other layer or notifies the other layer of some event. Whenever an Operational Primitive in invoked, the Connection_Handle qualifier is used to identify a particular iSCSI connection. For some Operational

接口要求由操作原语指定。操作原语是iSCSI层和iSER层之间的抽象功能接口过程,它请求一层代表另一层执行特定操作,或通知另一层某个事件。每当调用中的操作原语时,都会使用连接句柄限定符来标识特定的iSCSI连接。对于一些可操作的

Primitives, a Data_Descriptor is used to identify the iSCSI/SCSI data buffer associated with the requested or completed operation.

原语,数据描述符用于标识与请求的或完成的操作相关联的iSCSI/SCSI数据缓冲区。

The abstract model and the Operational Primitives defined in this section facilitate the description of the iSER protocol. In the rest of the iSER specification, the compliance statements related to the use of these Operational Primitives are only for the purpose of the required interactions between the iSCSI layer and the iSER layer. Note that the compliance statements related to the Operational Primitives in the rest of this specification only mandate functional equivalence on implementations, but do not put any requirements on the implementation specifics of the interface between the iSCSI layer and the iSER layer.

本节中定义的抽象模型和操作原语便于描述iSER协议。在iSER规范的其余部分中,与使用这些操作原语相关的符合性声明仅用于iSCSI层和iSER层之间所需的交互。请注意,本规范其余部分中与操作原语相关的合规性声明仅要求实现功能等效,但没有对iSCSI层和iSER层之间接口的实现细节提出任何要求。

Each Operational Primitive is invoked with a set of qualifiers that specify the information context for performing the specific action being requested of the Operational Primitive. While the qualifiers are required, the method of realizing the qualifiers (e.g., by passing synchronously with invocation, or by retrieving from task context, or by retrieving from shared memory, etc.) is implementation dependent.

使用一组限定符调用每个操作原语,这些限定符指定执行操作原语请求的特定操作的信息上下文。虽然需要限定符,但实现限定符的方法(例如,通过调用同步传递,或通过从任务上下文检索,或通过从共享内存检索等)取决于实现。

3.1. Operational Primitives Offered by iSER
3.1. iSER提供的操作原语

The iSER protocol layer MUST support the following Operational Primitives to be used by the iSCSI protocol layer.

iSER协议层必须支持iSCSI协议层使用的以下操作原语。

3.1.1. Send_Control
3.1.1. 发送控制

Input qualifiers: Connection_Handle, BHS and AHS (if any) of the iSCSI PDU, PDU-specific qualifiers

输入限定符:iSCSI PDU的连接句柄、BHS和AHS(如果有)、PDU特定限定符

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layers at the initiator and the target to request the outbound transfer of an iSCSI control-type PDU (see Section 7.2). Qualifiers that only apply for a particular control-type PDU are known as PDU-specific qualifiers, e.g., ImmediateDataSize for a SCSI write command. For details on PDU-specific qualifiers, see Section 7.3. The iSCSI layer can only invoke the Send_Control Operational Primitive when the connection is in iSER-assisted mode.

发起方和目标方的iSCSI层使用此功能请求iSCSI控制类型PDU的出站传输(请参阅第7.2节)。仅适用于特定控制类型PDU的限定符称为特定于PDU的限定符,例如SCSI写入命令的ImmediateDataSize。有关PDU特定限定符的详细信息,请参阅第7.3节。iSCSI层只能在连接处于iSER辅助模式时调用发送控制操作原语。

3.1.2. Put_Data
3.1.2. 输入数据

Input qualifiers: Connection_Handle, content of a SCSI Data-in PDU header, Data_Descriptor, Notify_Enable

输入限定符:连接句柄、PDU头中SCSI数据的内容、数据描述符、通知启用

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layer at the target to request the outbound transfer of data for a SCSI Data-in PDU from the buffer identified by the Data_Descriptor qualifier. The iSCSI layer can only invoke the Put_Data Operational Primitive when the connection is in iSER-assisted mode.

这被目标的iSCSI层用于从data_描述符限定符标识的缓冲区请求PDU中SCSI数据的出站传输。iSCSI层只能在连接处于iSER辅助模式时调用Put_数据操作原语。

The Notify_Enable qualifier is used to indicate to the iSER layer whether or not it should generate an eventual local completion notification to the iSCSI layer. See Section 3.2.2 on Data_Completion_Notify for details.

Notify_Enable限定符用于向iSER层指示是否应向iSCSI层生成最终的本地完成通知。有关详细信息,请参见第3.2.2节“数据完成通知”。

3.1.3. Get_Data
3.1.3. 获取数据

Input qualifiers: Connection_Handle, content of an R2T PDU, Data_Descriptor, Notify_Enable

输入限定符:连接句柄、R2T PDU的内容、数据描述符、通知启用

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layer at the target to request the inbound transfer of solicited data requested by an R2T PDU into the buffer identified by the Data_Descriptor qualifier. The iSCSI layer can only invoke the Get_Data Operational Primitive when the connection is in iSER-assisted mode.

目标端的iSCSI层使用此命令请求将R2T PDU请求的请求数据传入数据描述符限定符标识的缓冲区。iSCSI层只能在连接处于iSER辅助模式时调用Get_数据操作原语。

The Notify_Enable qualifier is used to indicate to the iSER layer whether or not it should generate the eventual local completion notification to the iSCSI layer. See Section 3.2.2 on Data_Completion_Notify for details.

Notify_Enable限定符用于向iSER层指示是否应向iSCSI层生成最终的本地完成通知。有关详细信息,请参见第3.2.2节“数据完成通知”。

3.1.4. Allocate_Connection_Resources
3.1.4. 分配连接资源

Input qualifiers: Connection_Handle, Resource_Descriptor (optional)

输入限定符:连接\句柄、资源\描述符(可选)

Return results: Status

返回结果:状态

This is used by the iSCSI layers at the initiator and the target to request the allocation of all connection resources necessary to support RCaP for an operational iSCSI/iSER connection. The iSCSI layer may optionally specify the implementation-specific resource requirements for the iSCSI connection using the Resource_Descriptor qualifier.

这由启动器和目标的iSCSI层用于请求分配所有必要的连接资源,以支持RCaP以实现可操作的iSCSI/iSER连接。iSCSI层可以选择使用资源描述符限定符为iSCSI连接指定特定于实现的资源要求。

A return result of Status=success means that the invocation succeeded, and a return result of Status=failure means that the invocation failed. If the invocation is for a Connection_Handle for

返回结果Status=success表示调用成功,返回结果Status=failure表示调用失败。如果调用是针对的连接\u句柄

which an earlier invocation succeeded, the request will be ignored by the iSER layer and the result of Status=success will be returned. Only one Allocate_Connection_Resources Operational Primitive invocation can be outstanding for a given Connection_Handle at any time.

如果先前的调用成功,iSER层将忽略该请求,并返回Status=success的结果。在任何时候,对于给定的连接句柄,只能有一个分配连接资源操作原语调用未完成。

3.1.5. Deallocate_Connection_Resources
3.1.5. 取消分配\u连接\u资源

Input qualifiers: Connection_Handle

输入限定符:连接\u句柄

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layers at the initiator and the target to request the deallocation of all connection resources that were allocated earlier as a result of a successful invocation of the Allocate_Connection_Resources Operational Primitive.

这被启动器和目标的iSCSI层用来请求解除分配由于成功调用Allocate_connection_resources操作原语而先前分配的所有连接资源。

3.1.6. Enable_Datamover
3.1.6. 启用数据移动器

Input qualifiers: Connection_Handle, Transport_Connection_Descriptor, Final Login_Response_PDU (optional)

输入限定符:连接\句柄、传输\连接\描述符、最终登录\响应\ PDU(可选)

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layers at the initiator and the target to request that a specified iSCSI connection be transitioned to iSER-assisted mode. The Transport_Connection_Descriptor qualifier is used to identify the specific connection associated with the Connection_Handle. The iSCSI layer can only invoke the Enable_Datamover Operational Primitive when there is a corresponding prior resource allocation.

这由启动器和目标的iSCSI层用于请求将指定的iSCSI连接转换为iSER辅助模式。传输\连接\描述符限定符用于标识与连接\句柄关联的特定连接。iSCSI层只能在有相应的先前资源分配时调用Enable_Datamover操作原语。

The Final_Login_Response_PDU input qualifier is applicable only for a target, and contains the final Login Response PDU that concludes the iSCSI Login Phase. If the underlying transport is TCP, the final Login Response PDU must be sent as a byte stream as expected by the iSCSI layer at the initiator. When this qualifier is used, the iSER layer at the target MUST transmit this final Login Response PDU before transitioning to iSER-assisted mode.

最终登录响应PDU输入限定符仅适用于目标,并包含结束iSCSI登录阶段的最终登录响应PDU。如果基础传输是TCP,则最终登录响应PDU必须按照启动器上iSCSI层的预期作为字节流发送。当使用此限定符时,目标的iSER层必须在转换到iSER辅助模式之前传输此最终登录响应PDU。

3.1.7. Connection_Terminate
3.1.7. 连接终止

Input qualifiers: Connection_Handle

输入限定符:连接\u句柄

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layers at the initiator and the target to request that a specified iSCSI/iSER connection be terminated and all associated connection and task resources be freed. When this Operational Primitive invocation returns to the iSCSI layer, the iSCSI layer may assume full ownership of all iSCSI-level resources, e.g., I/O Buffers, associated with the connection.

启动器和目标的iSCSI层使用此命令来请求终止指定的iSCSI/iSER连接并释放所有关联的连接和任务资源。当此操作原语调用返回到iSCSI层时,iSCSI层可能会承担与连接相关的所有iSCSI级别资源(例如I/O缓冲区)的完全所有权。

3.1.8. Notice_Key_Values
3.1.8. 注意\u键\u值

Input qualifiers: Connection_Handle, number of keys, list of Key-Value pairs

输入限定符:连接句柄、键数、键值对列表

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layers at the initiator and the target to request that the iSER layer take note of the specified Key-Value pairs that were negotiated by the iSCSI peers for the connection.

这被启动器和目标的iSCSI层用来请求iSER层记录iSCSI对等方为连接协商的指定键值对。

3.1.9. Deallocate_Task_Resources
3.1.9. 解除分配任务资源

Input qualifiers: Connection_Handle, ITT

输入限定符:连接句柄,ITT

Return results: Not specified

返回结果:未指定

This is used by the iSCSI layers at the initiator and the target to request the deallocation of all RCaP-specific resources allocated by the iSER layer for the task identified by the ITT qualifier. The iSER layer may require a certain number of RCaP-specific resources associated with the ITT for each new iSCSI task. In the normal course of execution, these task-level resources in the iSER layer are assumed to be transparently allocated on each task initiation and deallocated on the conclusion of each task as appropriate. In exception scenarios where the task does not conclude with a SCSI Response PDU, the iSER layer needs to be notified of the individual task terminations to aid its task-level resource management. This Operational Primitive is used for this purpose, and is not needed when a SCSI Response PDU normally concludes a task. Note that RCaP-specific task resources are deallocated by the iSER layer when a SCSI Response PDU normally concludes a task, even if the SCSI status was not success.

发起方和目标方的iSCSI层使用此命令请求解除分配iSER层为ITT限定符标识的任务分配的所有RCaP特定资源。对于每个新的iSCSI任务,iSER层可能需要一定数量的与ITT相关联的RCaP特定资源。在正常执行过程中,假定iSER层中的这些任务级资源在每个任务启动时透明分配,并在每个任务结束时酌情取消分配。在任务未以SCSI响应PDU结束的异常情况下,需要通知iSER层各个任务的终止,以帮助其任务级资源管理。此操作原语用于此目的,在SCSI响应PDU正常结束任务时不需要此原语。请注意,当SCSI响应PDU正常结束任务时,即使SCSI状态不是success,iSER层也会释放RCaP特定的任务资源。

3.2. Operational Primitives Used by iSER
3.2. iSER使用的操作原语

The iSER layer MUST use the following Operational Primitives offered by the iSCSI protocol layer when the connection is in iSER-assisted mode.

当连接处于iSER辅助模式时,iSER层必须使用iSCSI协议层提供的以下操作原语。

3.2.1. Control_Notify
3.2.1. 控制通知

Input qualifiers: Connection_Handle, an iSCSI control-type PDU

输入限定符:连接\ U句柄,iSCSI控制类型PDU

Return results: Not specified

返回结果:未指定

This is used by the iSER layers at the initiator and the target to notify the iSCSI layer of the availability of an inbound iSCSI control-type PDU. A PDU is described as "available" to the iSCSI layer when the iSER layer notifies the iSCSI layer of the reception of that inbound PDU, along with an implementation-specific indication as to where the received PDU is.

发起方和目标方的iSER层使用此命令通知iSCSI层入站iSCSI控制类型PDU的可用性。当iSER层通知iSCSI层接收到该入站PDU时,PDU被描述为对iSCSI层“可用”,并带有关于接收到的PDU所在位置的特定于实现的指示。

3.2.2. Data_Completion_Notify
3.2.2. 数据完成通知

Input qualifiers: Connection_Handle, ITT, SN

输入限定符:连接句柄、ITT、SN

Return results: Not specified

返回结果:未指定

This is used by the iSER layer to notify the iSCSI layer of the completion of outbound data transfer that was requested by the iSCSI layer only if the invocation of the Put_Data Operational Primitive (see Section 3.1.2) was qualified with Notify_Enable set. SN refers to the DataSN associated with the SCSI Data-in PDU.

iSER层使用它来通知iSCSI层,只有在调用Put_数据操作原语(参见第3.1.2节)符合notify_Enable set时,iSCSI层才请求完成出站数据传输。SN是指与PDU中的SCSI数据关联的数据SN。

This is used by the iSER layer to notify the iSCSI layer of the completion of inbound data transfer that was requested by the iSCSI layer only if the invocation of the Get_Data Operational Primitive (see Section 3.1.3) was qualified with Notify_Enable set. SN refers to the R2TSN associated with the R2T PDU.

iSER层使用它来通知iSCSI层,只有在调用Get_数据操作原语(参见第3.1.3节)符合notify_Enable set时,iSCSI层才请求完成入站数据传输。SN是指与R2T PDU关联的R2TSN。

3.2.3. Data_ACK_Notify
3.2.3. 数据确认通知

Input qualifier: Connection_Handle, ITT, DataSN

输入限定符:连接句柄、ITT、DataSN

Return results: Not specified

返回结果:未指定

This is used by the iSER layer at the target to notify the iSCSI layer of the arrival of the data acknowledgement (as defined in [RFC3720]) requested earlier by the iSCSI layer for the outbound data transfer via an invocation of the Put_Data Operational Primitive where the A-bit in the SCSI Data-in PDU is set to 1. See Section 7.3.5. DataSN refers to the expected DataSN of the next SCSI Data-in PDU, which immediately follows the SCSI Data-in PDU with the A-bit set to which this notification corresponds, with semantics as defined in [RFC3720].

目标端的iSER层使用该命令来通知iSCSI层,iSCSI层先前通过调用Put_数据操作原语请求的数据确认(如[RFC3720]中所定义)已到达,其中PDU中SCSI数据中的A位设置为1。见第7.3.5节。DataSN是指PDU中下一个SCSI数据的预期DataSN,它紧跟在PDU中的SCSI数据之后,带有此通知对应的A位集,语义如[RFC3720]中所定义。

3.2.4. Connection_Terminate_Notify
3.2.4. 连接\u终止\u通知

Input qualifiers: Connection_Handle

输入限定符:连接\u句柄

Return results: Not specified

返回结果:未指定

This is used by the iSER layers at the initiator and the target to notify the iSCSI layer of the unsolicited termination or failure of an iSCSI/iSER connection. The iSER layer MUST deallocate the connection and task resources associated with the terminated connection before the invocation of this Operational Primitive. Note that the Connection_Terminate_Notify Operational Primitive is not invoked when the termination of the connection is earlier requested by the local iSCSI layer.

发起方和目标方的iSER层使用此消息通知iSCSI层iSCSI/iSER连接的非请求终止或故障。iSER层必须在调用此操作原语之前解除分配与终止连接关联的连接和任务资源。请注意,当本地iSCSI层提前请求终止连接时,不会调用Connection_Terminate_Notify操作原语。

3.3. iSCSI Protocol Usage Requirements
3.3. iSCSI协议使用要求

To operate in an iSER-assisted mode, the iSCSI layers at both the initiator and the target MUST negotiate the RDMAExtensions key (see Section 6.3) to "Yes" on the leading connection. If the RDMAExtensions key is not negotiated to "Yes", then iSER-assisted mode MUST NOT be used. If the RDMAExtensions key is negotiated to "Yes" but the invocation of the Allocate_Connection_Resources Operational Primitive to the iSER layer fails, the iSCSI layer MUST fail the iSCSI Login process or terminate the connection as appropriate. See Section 10.1.3.1 for details.

要在iSER辅助模式下运行,发起方和目标方的iSCSI层必须在主要连接上将RDMAExtensions密钥(请参阅第6.3节)协商为“是”。如果RDMAExtensions密钥未协商为“是”,则不得使用iSER辅助模式。如果RDMAExtensions密钥协商为“是”,但向iSER层调用Allocate_Connection_Resources操作原语失败,则iSCSI层必须使iSCSI登录过程失败,或视情况终止连接。详见第10.1.3.1节。

If the RDMAExtensions key is negotiated to "Yes", the iSCSI layer MUST satisfy the following protocol usage requirements from the iSER protocol:

如果RDMAExtensions密钥协商为“是”,则iSCSI层必须满足iSER协议的以下协议使用要求:

1. The iSCSI layer at the initiator MUST set ExpDataSN to 0 in Task Management Function Requests for Task Allegiance Reassignment for read/bidirectional commands, so as to cause the target to send all unacknowledged read data.

1. 启动器处的iSCSI层必须在任务管理功能请求中将EXPDASCN设置为0,以便为读取/双向命令重新分配任务忠诚,从而使目标发送所有未确认的读取数据。

2. The iSCSI layer at the target MUST always return the SCSI status in a separate SCSI Response PDU for read commands, i.e., there MUST NOT be a "phase collapse" in concluding a SCSI read command.

2. 目标位置的iSCSI层必须始终在单独的SCSI响应PDU中为读取命令返回SCSI状态,即在结束SCSI读取命令时不得出现“阶段崩溃”。

3. The iSCSI layers at both the initiator and the target MUST support the keys as defined in Section 6 on Login/Text Operational Keys. If used as specified, these keys MUST NOT be answered with NotUnderstood, and the semantics as defined MUST be followed for each iSER-assisted connection.

3. 启动器和目标的iSCSI层都必须支持第6节“登录/文本操作密钥”中定义的密钥。如果按规定使用,这些键不能用NotUnderstanding来回答,并且每个iSER辅助连接都必须遵循定义的语义。

4. The iSCSI layer at the initiator MUST NOT issue SNACKs for PDUs.

4. 启动器处的iSCSI层不得为PDU发出零食。

4. Lower Layer Interface Requirements
4. 低层接口要求
4.1. Interactions with the RCaP Layer
4.1. 与RCaP层的相互作用

The iSER protocol layer is layered on top of an RCaP layer (see Figure 1) and the following are the key features that are assumed to be supported by any RCaP layer:

iSER协议层分层在RCaP层之上(见图1),以下是假定任何RCaP层都支持的关键功能:

* The RCaP layer supports all basic RDMA operations, including RDMA Write Operation, RDMA Read Operation, Send Operation, Send with Invalidate Operation, Send with Solicited Event Operation, Send with Solicited Event and Invalidate Operation, and Terminate Operation.

* RCaP层支持所有基本的RDMA操作,包括RDMA写操作、RDMA读操作、发送操作、发送无效操作、发送请求事件操作、发送请求事件和无效操作以及终止操作。

* The RCaP layer provides reliable, in-order message delivery and direct data placement.

* RCaP层提供可靠、有序的消息传递和直接的数据放置。

* When the iSER layer initiates an RDMA Read Operation following an RDMA Write Operation on one RCaP Stream, the RDMA Read Response Message processing on the remote node will be started only after the preceding RDMA Write Message payload is placed in the memory of the remote node.

* 当iSER层在一个RCaP流上的RDMA写入操作之后启动RDMA读取操作时,只有在将前面的RDMA写入消息有效负载放入远程节点的内存中之后,远程节点上的RDMA读取响应消息处理才会启动。

* The RCaP layer encapsulates a single iSER Message into a single RCaP Message on the Data Source side. The RCaP layer decapsulates the iSER Message before delivering it to the iSER layer on the Data Sink side.

* RCaP层在数据源端将单个iSER消息封装为单个RCaP消息。RCaP层在将iSER消息传送到数据接收器侧的iSER层之前,对其进行去封装。

* When the iSER layer provides the STag to be remotely invalidated to the RCaP layer for a SendInvSE Message, the RCaP layer uses this STag as the STag to be invalidated in the SendInvSE Message.

* 当iSER层为发送INVSE消息的RCaP层提供要远程失效的STag时,RCaP层使用该STag作为发送INVSE消息中要失效的STag。

* The RCaP layer uses the STag and Tagged Offset provided by the iSER layer for the RDMA Write and RDMA Read Request Messages.

* RCaP层使用iSER层为RDMA写入和RDMA读取请求消息提供的STag和标记偏移量。

* When the RCaP layer delivers the content of an RDMA Send Message Type to the iSER layer, the RCaP layer provides the length of the RDMA Send message. This ensures that the iSER layer does not have to carry a length field in the iSER header.

* 当RCaP层将RDMA发送消息类型的内容发送到iSER层时,RCaP层提供RDMA发送消息的长度。这确保iSER层不必在iSER头中携带长度字段。

* When the RCaP layer delivers the SendSE or SendInvSE Message to the iSER layer, it notifies the iSER layer with the mechanism provided on that interface.

* 当RCaP层将SendSE或SendInvSE消息传递给iSER层时,它会使用该接口上提供的机制通知iSER层。

* When the RCaP layer delivers a SendInvSE Message to the iSER layer, it passes the value of the STag that was invalidated.

* 当RCaP层向iSER层传递SendInvSE消息时,它会传递失效的STag值。

* The RCaP layer propagates all status and error indications to the iSER layer.

* RCaP层将所有状态和错误指示传播到iSER层。

* For a transport layer that operates in byte stream mode such as TCP, the RCaP implementation supports the enabling of the RDMA mode after connection establishment and the exchange of Login parameters in byte stream mode. For a transport layer that provides message delivery capability such as [IB], the RCaP implementation supports the use of the messaging capability by the iSCSI layer directly for the Login Phase after connection establishment before enabling iSER-assisted mode.

* 对于在字节流模式(如TCP)下运行的传输层,RCaP实现支持在建立连接后启用RDMA模式,并在字节流模式下交换登录参数。对于提供消息传递功能(如[IB])的传输层,RCaP实现支持iSCSI层在启用iSER辅助模式之前,在连接建立后的登录阶段直接使用消息传递功能。

* Whenever the iSER layer terminates the RCaP Stream, the RCaP layer terminates the associated connection.

* 每当iSER层终止RCaP流时,RCaP层终止关联的连接。

4.2. Interactions with the Transport Layer
4.2. 与传输层的相互作用

The iSER layer does not directly setup the transport layer connection (e.g., TCP, or [IB]). During connection setup, the iSCSI layer is responsible for setting up the connection. If the login is successful, the iSCSI layer invokes the Enable_Datamover Operational Primitive to request the iSER layer to transition to the iSER-assisted mode for that iSCSI connection. See Section 5.1 on iSCSI/iSER connection setup. After transitioning to iSER-assisted mode, the RCaP layer and the underlying transport layer are responsible for maintaining the connection and reporting to the iSER layer any connection failures.

iSER层不直接设置传输层连接(例如TCP或[IB])。在连接设置期间,iSCSI层负责设置连接。如果登录成功,iSCSI层将调用Enable_Datamover操作原语,请求iSER层为该iSCSI连接转换到iSER辅助模式。请参阅关于iSCSI/iSER连接设置的第5.1节。转换到iSER辅助模式后,RCaP层和底层传输层负责维护连接并向iSER层报告任何连接故障。

5. Connection Setup and Termination
5. 连接设置和终止
5.1. iSCSI/iSER Connection Setup
5.1. iSCSI/iSER连接设置

During connection setup, the iSCSI layer at the initiator is responsible for establishing a connection with the target. After the connection is established, the iSCSI layers at the initiator and the target enter the Login Phase using the same rules as outlined in [RFC3720]. Transition to iSER-assisted mode occurs when the connection transitions into the iSCSI Full Feature Phase following a successful login negotiation between the initiator and the target in which iSER-assisted mode is negotiated and the connection resources necessary to support RCaP have been allocated at both the initiator and the target. The same connection MUST be used for both the iSCSI Login Phase and the subsequent iSER-assisted Full Feature Phase.

在连接设置过程中,启动器处的iSCSI层负责与目标建立连接。建立连接后,启动器和目标的iSCSI层使用[RFC3720]中概述的相同规则进入登录阶段。在发起方和目标方之间协商成功登录后,连接过渡到iSCSI完整功能阶段时,即发生向iSER辅助模式的过渡,在该阶段中,iSER辅助模式已协商,并且支持RCaP所需的连接资源已在发起方和目标方分配。iSCSI登录阶段和随后的iSER辅助全功能阶段必须使用相同的连接。

iSER-assisted mode MUST be enabled only if it is negotiated on the leading connection during the LoginOperationalNegotiation stage of the iSCSI Login Phase. iSER-assisted mode is negotiated using the RDMAExtensions=<boolean-value> key. Both the initiator and the

只有在iSCSI登录阶段的LoginOperationalNegotiation阶段在主要连接上协商iSER辅助模式时,才必须启用iSER辅助模式。iSER辅助模式使用RDMAExtensions=<boolean value>键协商。启动器和

target MUST exchange the RDMAExtensions key with the value set to "Yes" to enable iSER-assisted mode. If both the initiator and the target fail to negotiate the RDMAExtensions key set to "Yes", then the connection MUST continue with the login semantics as defined in [RFC3720]. If the RDMAExtensions key is not negotiated to Yes, then for some RCaP implementation (such as [IB]), the connection may need to be re-established in TCP capable mode. (For InfiniBand this will require an [IPoIB] type connection.)

目标必须将RDMAExtensions密钥的值设置为“是”,以启用iSER辅助模式。如果启动器和目标都未能协商设置为“是”的RDMAExtensions密钥,则连接必须按照[RFC3720]中定义的登录语义继续。如果RDMAExtensions密钥未协商为“是”,则对于某些RCaP实现(如[IB]),可能需要在支持TCP的模式下重新建立连接。(对于InfiniBand,这将需要[IPoIB]类型的连接。)

iSER-assisted mode is defined for a Normal session only and the RDMAExtensions key MUST NOT be negotiated for a Discovery session. Discovery sessions are always conducted using the transport layer as described in [RFC3720].

iSER辅助模式仅为正常会话定义,不得为发现会话协商RDMAExtensions密钥。发现会话始终使用[RFC3720]中所述的传输层进行。

An iSER enabled node is not required to initiate the RDMAExtensions key exchange if its preference is for the Traditional iSCSI mode. The RDMAExtensions key, if offered, MUST be sent in the first available Login Response or Login Request PDU in the LoginOperationalNegotiation stage. This is due to the fact that the value of some login parameters might depend on whether iSER-assisted mode is enabled.

如果支持iSER的节点首选传统iSCSI模式,则无需启动RDMAExtensions密钥交换。RDMAExtensions密钥(如果提供)必须在LoginOperationalNegotiation阶段的第一个可用登录响应或登录请求PDU中发送。这是因为某些登录参数的值可能取决于是否启用iSER辅助模式。

iSER-assisted mode is a session-wide attribute. If both the initiator and the target negotiate RDMAExtensions="Yes" on the leading connection of a session, then all subsequent connections of the same session MUST enable iSER-assisted mode without having to exchange an RDMAExtensions key during the iSCSI Login Phase.

iSER辅助模式是会话范围的属性。如果启动器和目标都在会话的主要连接上协商RDMAExtensions=“Yes”,则同一会话的所有后续连接都必须启用iSER辅助模式,而无需在iSCSI登录阶段交换RDMAExtensions密钥。

Conversely, if both the initiator and the target fail to negotiate RDMAExtensions to "Yes" on the leading connection of a session, then the RDMAExtensions key MUST NOT be negotiated further on any additional subsequent connection of the session.

相反,如果发起方和目标方未能在会话的主要连接上将RDMAExtensions协商为“是”,则不得在会话的任何其他后续连接上进一步协商RDMAExtensions密钥。

When the RDMAExtensions key is negotiated to "Yes", the HeaderDigest and the DataDigest keys MUST be negotiated to "None" on all iSCSI/iSER connections participating in that iSCSI session. This is because, for an iSCSI/iSER connection, RCaP is responsible for providing error detection that is at least as good as a 32-bit CRC for all iSER Messages. Furthermore, all SCSI Read data are sent using RDMA Write Messages instead of the SCSI Data-in PDUs, and all solicited SCSI write data are sent using RDMA Read Response Messages instead of the SCSI Data-out PDUs. HeaderDigest and DataDigest that apply to iSCSI PDUs, would not be appropriate for RDMA Read and RDMA Write operations used with iSER.

当RDMAExtensions密钥协商为“是”时,参与该iSCSI会话的所有iSCSI/iSER连接上的HeaderDigest和DataDigest密钥必须协商为“无”。这是因为,对于iSCSI/iSER连接,RCaP负责为所有iSER消息提供至少相当于32位CRC的错误检测。此外,所有SCSI读取数据都使用RDMA写入消息而不是PDU中的SCSI数据发送,所有请求的SCSI写入数据都使用RDMA读取响应消息而不是SCSI数据输出PDU发送。适用于iSCSI PDU的HeaderDigest和DataDigest不适用于iSER使用的RDMA读取和RDMA写入操作。

5.1.1. Initiator Behavior
5.1.1. 引发剂行为

If the outcome of the iSCSI negotiation is to enable iSER-assisted mode, then on the initiator side, prior to sending the Login Request with the T (Transit) bit set to 1 and the NSG (Next Stage) field set to FullFeaturePhase, the iSCSI layer MUST request that the iSER layer allocate the connection resources necessary to support RCaP by invoking the Allocate_Connection_Resources Operational Primitive. The connection resources required are defined by implementation and are outside the scope of this specification. The iSCSI layer may invoke the Notice_Key_Values Operational Primitive before invoking the Allocate_Connection_Resources Operational Primitive to request that the iSER layer take note of the negotiated values of the iSCSI keys for the connection. The specific keys to be passed as input qualifiers are implementation dependent. These may include, but are not limited to, MaxOutstandingR2T, ErrorRecoveryLevel, etc.

如果iSCSI协商的结果是启用iSER辅助模式,则在启动器端,在发送登录请求之前,T(传输)位设置为1,NSG(下一阶段)字段设置为FullFeaturePhase,iSCSI层必须通过调用allocate_connection_resources操作原语请求iSER层分配支持RCaP所需的连接资源。所需的连接资源由实现定义,不在本规范的范围内。iSCSI层可以在调用Allocate_Connection_Resources操作原语之前调用Notice_Key_Values操作原语,以请求iSER层记录连接的iSCSI密钥的协商值。作为输入限定符传递的特定键取决于实现。这些可能包括但不限于MaxOutstandingR2T、ErrorRecoveryLevel等。

To minimize the potential for a denial-of service attack, the iSCSI layer MUST NOT request that the iSER layer allocate the connection resources necessary to support RCaP until the iSCSI layer is sufficiently far along in the iSCSI Login Phase that it is reasonably certain that the peer side is not an attacker. In particular, if the Login Phase includes a SecurityNegotiation stage, the iSCSI layer MUST defer the connection resource allocation (i.e., invoking the Allocate_Connection_Resources Operational Primitive) to the LoginOperationalNegotiation stage [RFC3720] so that the resource allocation occurs after the authentication phase is completed.

为了将拒绝服务攻击的可能性降至最低,iSCSI层不得请求iSER层分配支持RCaP所需的连接资源,直到iSCSI层在iSCSI登录阶段足够远,可以合理地确定对等方不是攻击者。特别是,如果登录阶段包括SecurityNegotiation阶段,iSCSI层必须将连接资源分配(即调用Allocate_connection_Resources操作原语)推迟到LoginOperational协商阶段[RFC3720],以便在身份验证阶段完成后进行资源分配。

Among the connection resources allocated at the initiator is the Inbound RDMA Read Queue Depth (IRD). As described in Section 9.5.1, R2Ts are transformed by the target into RDMA Read operations. IRD limits the maximum number of simultaneously incoming outstanding RDMA Read Requests per an RCaP Stream from the target to the initiator. The required value of IRD is outside the scope of the iSER specification. The iSER layer at the initiator MUST set IRD to 1 or higher if R2Ts are to be used in the connection. However, the iSER layer at the initiator MAY set IRD to 0 based on implementation configuration, which indicates that no R2Ts will be used on that connection. Initially, the iSER-IRD value at the initiator SHOULD be set to the IRD value at the initiator and MUST NOT be more than the IRD value.

在启动器上分配的连接资源中包括入站RDMA读取队列深度(IRD)。如第9.5.1节所述,目标将R2T转换为RDMA读取操作。IRD限制每个RCaP流从目标到启动器的同时传入未完成RDMA读取请求的最大数量。IRD的要求值超出iSER规范的范围。如果要在连接中使用R2T,则启动器处的iSER层必须将IRD设置为1或更高。但是,启动器处的iSER层可以根据实现配置将IRD设置为0,这表示该连接上不会使用R2T。最初,启动器上的iSER IRD值应设置为启动器上的IRD值,且不得超过IRD值。

On the other hand, the Outbound RDMA Read Queue Depth (ORD) MAY be set to 0, since the iSER layer at the initiator does not issue RDMA Read Requests to the target.

另一方面,出站RDMA读取队列深度(ORD)可以设置为0,因为启动器处的iSER层不会向目标发出RDMA读取请求。

Failure to allocate the requested connection resources locally results in a login failure and its handling is described in Section 10.1.3.1.

未能在本地分配请求的连接资源会导致登录失败,其处理方法见第10.1.3.1节。

If the iSER layer at the initiator is successful in allocating the connection resources necessary to support RCaP, the following events MUST occur in the specified sequence:

如果启动器处的iSER层成功分配支持RCaP所需的连接资源,则必须按指定顺序发生以下事件:

1. The iSER layer MUST return a success status to the iSCSI layer in response to the Allocate_Connection_Resources Operational Primitive.

1. iSER层必须向iSCSI层返回成功状态,以响应分配连接资源操作原语。

2. After the target returns the Login Response with the T bit set to 1 and the NSG field set to FullFeaturePhase, and a status class of 0 (Success), the iSCSI layer MUST request that the iSER layer transition to iSER-assisted mode by invoking the Enable_Datamover Operational Primitive with the following qualifiers. (See Section 10.1.4.6 for the case when the status class is not Success.):

2. 目标返回登录响应后,T位设置为1,NSG字段设置为FullFeaturePhase,状态类为0(成功),iSCSI层必须通过调用带有以下限定符的Enable_Datamover操作原语,请求iSER层转换到iSER辅助模式。(状态类不成功的情况见第10.1.4.6节):

a. Connection_Handle that identifies the iSCSI connection.

a. 连接\标识iSCSI连接的U句柄。

b. Transport_Connection_Descriptor that identifies the specific transport connection associated with the Connection_Handle.

b. 传输连接描述符,用于标识与连接句柄关联的特定传输连接。

3. If necessary, the iSER layer should enable RCaP and transition the connection to iSER-assisted mode. When the RCaP is iWARP, then this step MUST be done. Not all RCaPs may need it depending on the RCaP Stream start-up state.

3. 如有必要,iSER层应启用RCaP并将连接转换到iSER辅助模式。当RCaP为iWARP时,则必须执行此步骤。并非所有RCaP都需要它,这取决于RCaP流启动状态。

4. The iSER layer MUST send the iSER Hello Message as the first iSER Message. See Section 5.1.3 on iSER Hello Exchange.

4. iSER层必须将iSER Hello消息作为第一条iSER消息发送。请参阅iSER Hello Exchange的第5.1.3节。

5.1.2. Target Behavior
5.1.2. 目标行为

If the outcome of the iSCSI negotiation is to enable iSER-assisted mode, then on the target side, prior to sending the Login Response with the T (Transit) bit set to 1 and the NSG (Next Stage) field set to FullFeaturePhase, the iSCSI layer MUST request that the iSER layer allocate the resources necessary to support RCaP by invoking the Allocate_Connection_Resources Operational Primitive. The connection resources required are defined by implementation and are outside the scope of this specification. Optionally, the iSCSI layer may invoke the Notice_Key_Values Operational Primitive before invoking the Allocate_Connection_Resources Operational Primitive to request that the iSER layer take note of the negotiated values of the iSCSI keys for the connection. The specific keys to be passed as input

如果iSCSI协商的结果是启用iSER辅助模式,则在目标端,在发送登录响应之前,T(传输)位设置为1,NSG(下一阶段)字段设置为FullFeaturePhase,iSCSI层必须通过调用allocate_Connection_resources操作原语请求iSER层分配支持RCaP所需的资源。所需的连接资源由实现定义,不在本规范的范围内。可选地,iSCSI层可以在调用Allocate_Connection_Resources操作原语之前调用Notice_Key_Values操作原语,以请求iSER层记录用于连接的iSCSI密钥的协商值。要作为输入传递的特定键

qualifiers are implementation dependent. These may include, but are not limited to, MaxOutstandingR2T, ErrorRecoveryLevel, etc.

限定符依赖于实现。这些可能包括但不限于MaxOutstandingR2T、ErrorRecoveryLevel等。

To minimize the potential for a denial-of-service attack, the iSCSI layer MUST NOT request that the iSER layer allocate the connection resources necessary to support RCaP until the iSCSI layer is sufficiently far along in the iSCSI Login Phase that it is reasonably certain that the peer side is not an attacker. In particular, if the Login Phase includes a SecurityNegotiation stage, the iSCSI layer MUST defer the connection resource allocation (i.e., invoking the Allocate_Connection_Resources Operational Primitive) to the LoginOperationalNegotiation stage [RFC3720] so that the resource allocation occurs after the authentication phase is completed.

为了将拒绝服务攻击的可能性降至最低,iSCSI层不得请求iSER层分配支持RCaP所需的连接资源,直到iSCSI层在iSCSI登录阶段足够远,可以合理地确定对等方不是攻击者。特别是,如果登录阶段包括SecurityNegotiation阶段,iSCSI层必须将连接资源分配(即调用Allocate_connection_Resources操作原语)推迟到LoginOperational协商阶段[RFC3720],以便在身份验证阶段完成后进行资源分配。

Among the connection resources allocated at the target is the Outbound RDMA Read Queue Depth (ORD). As described in Section 9.5.1, R2Ts are transformed by the target into RDMA Read operations. The ORD limits the maximum number of simultaneously outstanding RDMA Read Requests per RCaP Stream from the target to the initiator. Initially, the iSER-ORD value at the target SHOULD be set to the ORD value at the target.

在目标上分配的连接资源中包括出站RDMA读取队列深度(ORD)。如第9.5.1节所述,目标将R2T转换为RDMA读取操作。ORD限制从目标到启动器的每个RCaP流同时未完成的RDMA读取请求的最大数量。最初,目标处的iSER ORD值应设置为目标处的ORD值。

On the other hand, the IRD at the target MAY be set to 0 since the iSER layer at the target does not expect RDMA Read Requests to be issued by the initiator.

另一方面,目标处的IRD可以设置为0,因为目标处的iSER层不期望发起方发出RDMA读取请求。

Failure to allocate the requested connection resources locally results in a login failure and its handling is described in Section 10.1.3.1.

未能在本地分配请求的连接资源会导致登录失败,其处理方法见第10.1.3.1节。

If the iSER layer at the target is successful in allocating the connection resources necessary to support RCaP, the following events MUST occur in the specified sequence:

如果目标的iSER层成功分配支持RCaP所需的连接资源,则必须按指定顺序发生以下事件:

1. The iSER layer MUST return a success status to the iSCSI layer in response to the Allocate_Connection_Resources Operational Primitive.

1. iSER层必须向iSCSI层返回成功状态,以响应分配连接资源操作原语。

2. The iSCSI layer MUST request that the iSER layer transition to iSER-assisted mode by invoking the Enable_Datamover Operational Primitive with the following qualifiers:

2. iSCSI层必须通过调用带有以下限定符的Enable_Datamover操作原语,请求iSER层转换到iSER辅助模式:

a. Connection_Handle that identifies the iSCSI connection.

a. 连接\标识iSCSI连接的U句柄。

b. Transport_Connection_Descriptor that identifies the specific transport connection associated with the Connection_Handle.

b. 传输连接描述符,用于标识与连接句柄关联的特定传输连接。

c. The final transport layer (e.g., TCP) message containing the Login Response with the T bit set to 1 and the NSG field set to FullFeaturePhase.

c. 最后一个传输层(如TCP)消息,包含登录响应,T位设置为1,NSG字段设置为FullFeaturePhase。

3. The iSER layer MUST send the final Login Response PDU in the native transport mode to conclude the iSCSI Login Phase. If the underlying transport is TCP, then the iSER layer MUST send the final Login Response PDU in byte stream mode.

3. iSER层必须以本机传输模式发送最终登录响应PDU,以结束iSCSI登录阶段。如果底层传输是TCP,那么iSER层必须以字节流模式发送最终登录响应PDU。

4. After sending the final Login Response PDU, the iSER layer should enable RCaP if necessary and transition the connection to iSER-assisted mode. When the RCaP is iWARP, then this step MUST be done. Not all RCaPs may need it depending on the RCaP Stream start-up state.

4. 发送最终登录响应PDU后,iSER层应在必要时启用RCaP,并将连接转换为iSER辅助模式。当RCaP为iWARP时,则必须执行此步骤。并非所有RCaP都需要它,这取决于RCaP流启动状态。

5. After receiving the iSER Hello Message from the initiator, the iSER layer MUST respond with the iSER HelloReply Message to be sent as the first iSER Message. See Section 5.1.3 on iSER Hello Exchange for more details.

5. 在从启动器接收到iSER Hello消息后,iSER层必须以iSER HelloReply消息作为第一条iSER消息进行响应。有关更多详细信息,请参阅iSER Hello Exchange的第5.1.3节。

Note: In the above sequence, the operations as described in bullets 3 and 4 MUST be performed atomically for iWARP connections. Failure to do this may result in race conditions.

注意:在上述顺序中,项目符号3和4中描述的操作必须针对iWARP连接以原子方式执行。不这样做可能会导致比赛条件。

5.1.3. iSER Hello Exchange
5.1.3. 伊瑟尔你好交换

After the connection transitions into iSER-assisted mode, the first iSER Message sent by the iSER layer at the initiator to the target MUST be the iSER Hello Message. The iSER Hello Message is used by the iSER layer at the initiator to declare iSER parameters to the target. See Section 9.3 on iSER Header Format for the iSER Hello Message.

连接转换到iSER辅助模式后,iSER层在启动器处向目标发送的第一条iSER消息必须是iSER Hello消息。iSER Hello消息由发起方的iSER层用于向目标声明iSER参数。有关iSER Hello消息,请参见第9.3节iSER头格式。

In response to the iSER Hello Message, the iSER layer at the target MUST return the iSER HelloReply Message as the first iSER Message sent by the target. The iSER HelloReply Message is used by the iSER layer at the target to declare iSER parameters to the initiator. See Section 9.4 on iSER Header Format for the iSER HelloReply Message.

为了响应iSER Hello消息,目标的iSER层必须返回iSER HelloReply消息,作为目标发送的第一条iSER消息。目标的iSER层使用iSER HelloReply消息向启动器声明iSER参数。有关iSER HelloReply消息,请参见第9.4节iSER头格式。

In the iSER Hello Message, the iSER layer at the initiator declares the iSER-IRD value to the target.

在iSER Hello消息中,启动器处的iSER层向目标声明iSER IRD值。

Upon receiving the iSER Hello Message, the iSER layer at the target MUST set the iSER-ORD value to the minimum of the iSER-ORD value at the target and the iSER-IRD value declared by the initiator. The iSER layer at the target MAY adjust (lower) its ORD value to match the iSER-ORD value if the iSER-ORD value is smaller than the ORD value at the target in order to free up the unused resources.

收到iSER Hello消息后,目标的iSER层必须将iSER ORD值设置为目标的iSER ORD值和启动器声明的iSER IRD值中的最小值。如果iSER ORD值小于目标处的ORD值,则目标处的iSER层可以调整(降低)其ORD值以匹配iSER ORD值,以便释放未使用的资源。

In the iSER HelloReply Message, the iSER layer at the target declares the iSER-ORD value to the initiator.

在iSER HelloReply消息中,目标的iSER层向启动器声明iSER ORD值。

Upon receiving the iSER HelloReply Message, the iSER layer at the initiator MAY adjust (lower) its IRD value to match the iSER-ORD value in order to free up the unused resources, if the iSER-ORD value declared by the target is smaller than the iSER-IRD value declared by the initiator.

在接收到iSER HelloReply消息后,如果目标声明的iSER ORD值小于启动器声明的iSER IRD值,则启动器处的iSER层可以调整(降低)其IRD值以匹配iSER ORD值,以便释放未使用的资源。

It is an iSER level negotiation failure if the iSER parameters declared in the iSER Hello Message by the initiator are unacceptable to the target. This includes the following:

如果发起方在iSER Hello消息中声明的iSER参数对目标不可接受,则为iSER级协商失败。这包括:

* The initiator-declared iSER-IRD value is greater than 0 and the target-declared iSER-ORD value is 0.

* 启动器声明的iSER IRD值大于0,目标声明的iSER ORD值为0。

* The initiator-supported and the target-supported iSER protocol versions do not overlap.

* 受支持的启动器和受支持的目标iSER协议版本不重叠。

See Section 10.1.3.2 for the handling of the error situation.

错误情况的处理见第10.1.3.2节。

5.2. iSCSI/iSER Connection Termination
5.2. iSCSI/iSER连接终止
5.2.1. Normal Connection Termination at the Initiator
5.2.1. 启动器处的正常连接终止

The iSCSI layer at the initiator terminates an iSCSI/iSER connection normally by invoking the Send_Control Operational Primitive qualified with the Logout Request PDU. The iSER layer at the initiator MUST use a SendSE Message to send the Logout Request PDU to the target. After the iSER layer at the initiator receives the SendSE Message containing the Logout Response PDU from the target, it MUST notify the iSCSI layer by invoking the Control_Notify Operational Primitive qualified with the Logout Response PDU.

启动器处的iSCSI层通常通过调用使用注销请求PDU限定的发送控制操作原语来终止iSCSI/iSER连接。启动器处的iSER层必须使用SendSE消息将注销请求PDU发送到目标。在启动器的iSER层从目标接收到包含注销响应PDU的SendSE消息后,它必须通过调用使用注销响应PDU限定的Control_notify Operational原语来通知iSCSI层。

After the iSCSI logout process is complete, the iSCSI layer at the target is responsible for closing the iSCSI/iSER connection as described in Section 5.2.2. After the RCaP layer at the initiator reports that the connection has been closed, the iSER layer at the initiator MUST deallocate all connection and task resources (if any) associated with the connection, and invalidate the Local Mapping(s) (if any) that associate the ITT(s) used on that connection to the local STag(s) before notifying the iSCSI layer by invoking the Connection_Terminate_Notify Operational Primitive.

iSCSI注销过程完成后,目标位置的iSCSI层负责关闭iSCSI/iSER连接,如第5.2.2节所述。在启动器处的RCaP层报告连接已关闭后,启动器处的iSER层必须解除分配与该连接关联的所有连接和任务资源(如果有),并使将该连接上使用的ITT与本地STag关联的本地映射(如果有)无效在通过调用Connection\u Terminate\u Notify操作原语通知iSCSI层之前。

5.2.2. Normal Connection Termination at the Target
5.2.2. 目标上的正常连接终止

Upon receiving the SendSE Message containing the Logout Request PDU, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Control_Notify Operational Primitive qualified with the Logout Request PDU. The iSCSI layer completes the logout process by invoking the Send_Control Operational Primitive qualified with the Logout Response PDU. The iSER layer at the target MUST use a SendSE Message to send the Logout Response PDU to the initiator. After the iSCSI logout process is complete, the iSCSI layer at the target MUST request that the iSER layer at the target terminate the RCaP Stream by invoking the Connection_Terminate Operational Primitive.

接收到包含注销请求PDU的SendSE消息后,目标的iSER层必须通过调用注销请求PDU限定的Control_notify Operational原语来通知目标的iSCSI层。iSCSI层通过调用使用注销响应PDU限定的发送控制操作原语来完成注销过程。目标的iSER层必须使用SendSE消息将注销响应PDU发送给启动器。iSCSI注销过程完成后,目标的iSCSI层必须请求目标的iSER层通过调用Connection_terminate操作原语终止RCaP流。

As part of the termination process, the RCaP layer MUST close the connection. When the RCaP layer notifies the iSER layer after the RCaP Stream and the associated connection are terminated, the iSER layer MUST deallocate all connection and task resources (if any) associated with the connection, and invalidate the Local and Remote Mapping(s) (if any) that associate the ITT(s) used on that connection to the local STag(s) and the Advertised STag(s) respectively.

作为终止过程的一部分,RCaP层必须关闭连接。当RCaP层在RCaP流和相关连接终止后通知iSER层时,iSER层必须解除分配与该连接相关联的所有连接和任务资源(如果有),并使将该连接上使用的ITT与本地STag关联的本地和远程映射(如果有)无效以及广告中的雄鹿。

5.2.3. Termination without Logout Request/Response PDUs
5.2.3. 无注销请求/响应PDU的终止
5.2.3.1. Connection Termination Initiated by the iSCSI Layer
5.2.3.1. 由iSCSI层启动的连接终止

The Connection_Terminate Operational Primitive MAY be invoked by the iSCSI layer to request that the iSER layer terminate the RCaP Stream without having previously exchanged the Logout Request and Logout Response PDUs between the two iSCSI/iSER nodes. As part of the termination process, the RCaP layer will close the connection. When the RCaP layer notifies the iSER layer after the RCaP Stream and the associated connection are terminated, the iSER layer MUST perform the following actions.

iSCSI层可以调用Connection_Terminate操作原语,请求iSER层终止RCaP流,而无需事先在两个iSCSI/iSER节点之间交换注销请求和注销响应PDU。作为终止过程的一部分,RCaP层将关闭连接。当RCaP层在RCaP流和相关连接终止后通知iSER层时,iSER层必须执行以下操作。

If the Connection_Terminate Operational Primitive is invoked by the iSCSI layer at the target, then the iSER layer at the target MUST deallocate all connection and task resources (if any) associated with the connection, and invalidate the Local and Remote Mappings (if any) that associate the ITT(s) used on the connection to the local STag(s) and the Advertised STag(s), respectively.

如果目标上的iSCSI层调用了Connection_Terminate操作原语,则目标上的iSER层必须解除分配与该连接关联的所有连接和任务资源(如果有),并使将连接上使用的ITT与本地STag关联的本地和远程映射(如果有)无效和广告中的雄鹿。

If the Connection_Terminate Operational Primitive is invoked by the iSCSI layer at the initiator, then the iSER layer at the initiator MUST deallocate all connection and task resources (if any) associated with the connection, and invalidate the Local Mapping(s) (if any) that associate the ITT(s) used on the connection to the local STag(s).

如果启动器上的iSCSI层调用了Connection_Terminate操作原语,则启动器上的iSER层必须解除分配与连接关联的所有连接和任务资源(如果有),并使将连接上使用的ITT与本地STag关联的本地映射(如果有)无效。

5.2.3.2. Connection Termination Notification to the iSCSI Layer
5.2.3.2. 到iSCSI层的连接终止通知

If the iSCSI/iSER connection is terminated without the invocation of Connection_Terminate from the iSCSI layer, the iSER layer MUST notify the iSCSI layer that the iSCSI/iSER connection has been terminated by invoking the Connection_Terminate_Notify Operational Primitive.

如果iSCSI/iSER连接在没有从iSCSI层调用connection\u Terminate的情况下终止,则iSER层必须通过调用connection\u Terminate\u notify Operational原语通知iSCSI层iSCSI/iSER连接已终止。

Prior to invoking Connection_Terminate_Notify, the iSER layer at the target MUST deallocate all connection and task resources (if any) associated with the connection, and invalidate the Local and Remote Mappings (if any) that associate the ITT(s) used on the connection to the local STag(s) and the Advertised STag(s), respectively.

在调用Connection_Terminate_Notify之前,目标的iSER层必须解除分配与连接关联的所有连接和任务资源(如果有),并使本地和远程映射(如果有)无效,这些映射将连接上使用的ITT分别与本地STag和播发STag关联。

Prior to invoking Connection_Terminate_Notify, the iSER layer at the initiator MUST deallocate all connection and task resources (if any) associated with the connection, and invalidate the Local Mappings (if any) that associate the ITT(s) used on the connection to the local STag(s).

在调用Connection_Terminate_Notify之前,启动器上的iSER层必须解除分配与连接关联的所有连接和任务资源(如果有),并使连接上使用的ITT与本地STag关联的本地映射(如果有)无效。

If the remote iSCSI/iSER node initiated the closing of the connection (e.g., by sending a TCP FIN or TCP RST), the iSER layer MUST notify the iSCSI layer after the RCaP layer reports that the connection is closed by invoking the Connection_Terminate_Notify Operational Primitive.

如果远程iSCSI/iSER节点启动了连接关闭(例如,通过发送TCP FIN或TCP RST),则iSER层必须在RCaP层通过调用连接终止通知操作原语报告连接关闭后通知iSCSI层。

Another example of a connection termination without a preceding logout is when the iSCSI layer at the initiator does an implicit logout (connection reinstatement).

未事先注销的连接终止的另一个示例是启动器的iSCSI层执行隐式注销(连接恢复)。

6. Login/Text Operational Keys
6. 登录/文本操作键

Certain iSCSI login/text operational keys have restricted usage in iSER, and additional keys are used to support the iSER protocol functionality. All other keys defined in [RFC3720] and not discussed in this section may be used on iSCSI/iSER connections with the same semantics.

某些iSCSI登录/文本操作密钥在iSER中的使用受到限制,其他密钥用于支持iSER协议功能。[RFC3720]中定义且本节中未讨论的所有其他密钥可在具有相同语义的iSCSI/iSER连接上使用。

6.1. HeaderDigest and DataDigest
6.1. HeaderDigest和DataDigest

Irrelevant when: RDMAExtensions=Yes

当:RDMAExtensions=Yes时不相关

Negotiations resulting in RDMAExtensions=Yes for a session implies HeaderDigest=None and DataDigest=None for all connections in that session and overrides both the default and an explicit setting.

对于会话,导致RDMAExtensions=Yes的协商意味着该会话中所有连接的HeaderDigest=None和DataDigest=None,并覆盖默认设置和显式设置。

6.2. MaxRecvDataSegmentLength
6.2. MaxRecvDataSegmentLength

For an iSCSI connection belonging to a session in which RDMAExtensions=Yes was negotiated on the leading connection of the session, MaxRecvDataSegmentLength need not be declared in the Login Phase. Instead, InitiatorRecvDataSegmentLength (as described in Section 6.5) and TargetRecvDataSegmentLength (as described in Section 6.4) keys are negotiated. The values of the local and remote MaxRecvDataSegmentLength are derived from the InitiatorRecvDataSegmentLength and TargetRecvDataSegmentLength keys even if the MaxRecvDataSegmentLength is declared during the Login Phase.

对于属于会话的iSCSI连接,其中在会话的主要连接上协商了RDMAExtensions=Yes,则无需在登录阶段声明MaxRecvDataSegmentLength。相反,InitiatorRecvDataSegmentLength(如第6.5节所述)和TargetRecvDataSegmentLength(如第6.4节所述)密钥是协商的。本地和远程MaxRecvDataSegmentLength的值是从InitiatorRecvDataSegmentLength和TargetRecvDataSegmentLength键派生的,即使在登录阶段声明了MaxRecvDataSegmentLength。

In the Full Feature Phase, the initiator MUST consider the value of its local MaxRecvDataSegmentLength (that it would have declared to the target) as having the value of InitiatorRecvDataSegmentLength, and the value of the remote MaxRecvDataSegmentLength (that would have been declared by the target) as having the value of TargetRecvDataSegmentLength. Similarly, the target MUST consider the value of its local MaxRecvDataSegmentLength (that it would have declared to the initiator) as having the value of TargetRecvDataSegmentLength, and the value of the remote MaxRecvDataSegmentLength (that would have been declared by the initiator) as having the value of InitiatorRecvDataSegmentLength.

在整个特征阶段,发起人必须考虑其本地Max ReVDATA数据长度(它将已经声明给目标)的值,即具有RealActuvReDeaseGeMeTeNT的值,以及远程MaxRecvDataSegmentLength的值(这将是目标声明的)。具有TargetRecvDataSegmentLength的值。类似地,目标必须考虑其本地Max ReVDATA数据长度(它将已经声明给发起人)的值,作为目标RealVDATA数据长度的值,而远程MaxRecvDataSegmentLength的值(这将由发起人声明)具有初始值RealReValDeaseGeMeTrand的值。

The MaxRecvDataSegmentLength key is applicable only for iSCSI control-type PDUs.

MaxRecvDataSegmentLength密钥仅适用于iSCSI控制类型PDU。

6.3. RDMAExtensions
6.3. RDMAExtensions

Use: LO (leading only)

使用:LO(仅前导)

Senders: Initiator and Target

发件人:启动器和目标

Scope: SW (session-wide)

范围:软件(会话范围)

   RDMAExtensions=<boolean-value>
        
   RDMAExtensions=<boolean-value>
        

Irrelevant when: SessionType=Discovery

当:SessionType=Discovery时不相关

Default is No

默认为否

Result function is AND

结果函数为和

This key is used by the initiator and the target to negotiate support for iSER-assisted mode. To enable the use of iSER-assisted mode, both the initiator and the target MUST exchange RDMAExtensions=Yes.

发起方和目标方使用此密钥协商对iSER辅助模式的支持。要启用iSER辅助模式,发起方和目标方必须交换RDMAExtensions=Yes。

iSER-assisted mode MUST NOT be used if either the initiator or the target offers RDMAExtensions=No.

如果发起方或目标方提供RDMAExtensions=No,则不得使用iSER辅助模式。

An iSER-enabled node is not required to initiate the RDMAExtensions key exchange if it prefers to operate in the Traditional iSCSI mode. However, if the RDMAExtensions key is to be negotiated, an initiator MUST offer the key in the first Login Request PDU in the LoginOperationalNegotiation stage of the leading connection, and a target MUST offer the key in the first Login Response PDU with which it is allowed to do so (i.e., the first Login Response PDU issued after the first Login Request PDU with the C bit set to 0) in the LoginOperationalNegotiation stage of the leading connection. In response to the offered key=value pair of RDMAExtensions=yes, an initiator MUST respond in the next Login Request PDU with which it is allowed to do so, and a target MUST respond in the next Login Response PDU with which it is allowed to do so.

如果启用iSER的节点希望在传统iSCSI模式下运行,则无需启动RDMAExtensions密钥交换。但是,如果要协商RDMAExtensions密钥,则发起方必须在领先连接的LoginOperationalNegotiation阶段的第一个登录请求PDU中提供密钥,而目标方必须在允许其这样做的第一个登录响应PDU中提供密钥(即,在C位设置为0的第一个登录请求PDU之后发出的第一个登录响应PDU)在领先连接的LoginOperationalNegotiation阶段。为了响应提供的RDMAExtensions=yes的key=value对,发起方必须在允许其响应的下一个登录请求PDU中响应,目标方必须在允许其响应的下一个登录响应PDU中响应。

Negotiating the RDMAExtensions key first enables a node to negotiate the optimal value for other keys. Certain iSCSI keys such as MaxBurstLength, MaxOutstandingR2T, ErrorRecoveryLevel, InitialR2T, ImmediateData, etc., may be negotiated differently depending on whether the connection is in Traditional iSCSI mode or iSER-assisted mode.

协商RDMAExtensions密钥首先使节点能够协商其他密钥的最佳值。某些iSCSI密钥(如MaxBurstLength、MaxOutstandingR2T、ErrorRecoveryLevel、InitialR2T、ImmediateData等)的协商方式可能会有所不同,具体取决于连接处于传统iSCSI模式还是iSER辅助模式。

6.4. TargetRecvDataSegmentLength
6.4. TargetRecvDataSegmentLength

Use: IO (Initialize only)

使用:IO(仅初始化)

Senders: Initiator and Target

发件人:启动器和目标

Scope: CO (connection-only)

经营范围:CO(仅限连接)

Irrelevant when: RDMAExtensions=No

当:RDMAExtensions=No时不相关

   TargetRecvDataSegmentLength=<numerical-value-512-to-(2**24-1)>
        
   TargetRecvDataSegmentLength=<numerical-value-512-to-(2**24-1)>
        

Default is 8192 bytes

默认值为8192字节

Result function is minimum

结果函数是最小的

This key is relevant only for the iSCSI connection of an iSCSI session if RDMAExtensions=Yes is negotiated on the leading connection of the session. It is used by the initiator and target to negotiate the maximum size of the data segment that an initiator may send to the target in an iSCSI control-type PDU in the Full Feature Phase. For SCSI Command PDUs and SCSI Data-out PDUs containing non-immediate unsolicited data to be sent by the initiator, the initiator MUST send all non-Final PDUs with a data segment size of exactly

如果在会话的主要连接上协商RDMAExtensions=Yes,则此密钥仅与iSCSI会话的iSCSI连接相关。启动器和目标使用它来协商在完整功能阶段,启动器可以通过iSCSI控制类型PDU向目标发送的数据段的最大大小。对于包含要由启动器发送的非即时非请求数据的SCSI命令PDU和SCSI数据输出PDU,启动器必须发送数据段大小为的所有非最终PDU

TargetRecvDataSegmentLength whenever the PDUs constitute a data sequence whose size is larger than TargetRecvDataSegmentLength.

每当PDU构成的数据序列的大小大于TargetRecvDataSegmentLength时,TargetRecvDataSegmentLength。

6.5. InitiatorRecvDataSegmentLength
6.5. InitiatorRecvDataSegmentLength

Use: IO (Initialize only)

使用:IO(仅初始化)

Senders: Initiator and Target

发件人:启动器和目标

Scope: CO (connection-only)

经营范围:CO(仅限连接)

Irrelevant when: RDMAExtensions=No

当:RDMAExtensions=No时不相关

   InitiatorRecvDataSegmentLength=<numerical-value-512-to-(2**24-1)>
        
   InitiatorRecvDataSegmentLength=<numerical-value-512-to-(2**24-1)>
        

Default is 8192 bytes

默认值为8192字节

Result function is minimum

结果函数是最小的

This key is relevant only for the iSCSI connection of an iSCSI session if RDMAExtensions=Yes is negotiated on the leading connection of the session. It is used by the initiator and target to negotiate the maximum size of the data segment that a target may send to the initiator in an iSCSI control-type PDU in the Full Feature Phase.

如果在会话的主要连接上协商RDMAExtensions=Yes,则此密钥仅与iSCSI会话的iSCSI连接相关。启动器和目标使用它来协商在完整功能阶段目标可以通过iSCSI控制类型PDU发送给启动器的数据段的最大大小。

6.6. OFMarker and IFMarker
6.6. Marker和IFMarker的定义

Irrelevant when: RDMAExtensions=Yes

当:RDMAExtensions=Yes时不相关

Negotiations resulting in RDMAExtensions=Yes for a session implies OFMarker=No and IFMarker=No for all connections in that session and overrides both the default and an explicit setting.

对于会话,导致RDMAExtensions=Yes的协商意味着该会话中所有连接的marker=No和IFMarker=No,并覆盖默认设置和显式设置。

6.7. MaxOutstandingUnexpectedPDUs
6.7. 最大未预期PDU

Use: LO (leading only), Declarative

用法:LO(仅前导),声明性

Senders: Initiator and Target

发件人:启动器和目标

Scope: SW (session-wide)

范围:软件(会话范围)

Irrelevant when: RDMAExtensions=No

当:RDMAExtensions=No时不相关

   MaxOutstandingUnexpectedPDUs=<numerical-value-from-2-to-(2**32-1) |
   0>
        
   MaxOutstandingUnexpectedPDUs=<numerical-value-from-2-to-(2**32-1) |
   0>
        

Default is 0

默认值为0

This key is used by the initiator and the target to declare the maximum number of outstanding "unexpected" iSCSI control-type PDUs that it can receive in the Full Feature Phase. It is intended to allow the receiving side to determine the amount of buffer resources needed beyond the normal flow control mechanism available in iSCSI. An initiator or target should select a value such that it would not impose an unnecessary constraint on the iSCSI layer under normal circumstances. The value of 0 is defined to indicate that the declarer has no limit on the maximum number of outstanding "unexpected" iSCSI control-type PDUs that it can receive. See Sections 8.1.1 and 8.1.2 for the usage of this key. Note that iSER Hello and HelloReply Messages are not iSCSI control-type PDUs and are not affected by this key.

启动器和目标使用此密钥来声明在完整功能阶段可接收的最大未完成“意外”iSCSI控制类型PDU数。其目的是允许接收端确定超出iSCSI中可用的正常流量控制机制所需的缓冲区资源量。启动器或目标应选择一个值,以便在正常情况下不会对iSCSI层施加不必要的约束。定义值0表示申报人对其可以接收的未完成“意外”iSCSI控制类型PDU的最大数量没有限制。有关此键的用法,请参见第8.1.1节和第8.1.2节。请注意,iSER Hello和HelloReply消息不是iSCSI控制类型PDU,不受此密钥的影响。

7. iSCSI PDU Considerations
7. iSCSI PDU注意事项

When a connection is in the iSER-assisted mode, two types of message transfers are allowed between the iSCSI layer at the initiator and the iSCSI layer at the target. These are known as the iSCSI data-type PDUs and the iSCSI control-type PDUs, and these terms are described in the following sections.

当连接处于iSER辅助模式时,在启动器的iSCSI层和目标的iSCSI层之间允许两种类型的消息传输。这些称为iSCSI数据类型PDU和iSCSI控制类型PDU,以下各节将介绍这些术语。

7.1. iSCSI Data-Type PDU
7.1. iSCSI数据类型PDU

An iSCSI data-type PDU is defined as an iSCSI PDU that causes data transfer, transparent to the remote iSCSI layer, to take place between the peer iSCSI nodes in the full feature phase of an iSCSI/iSER connection. An iSCSI data-type PDU, when requested for transmission by the iSCSI layer in the sending node, results in the data being transferred without the participation of the iSCSI layers at the sending and the receiving nodes. This is due to the fact that the PDU itself is not delivered as-is to the iSCSI layer in the receiving node. Instead, the data transfer operations are transformed into the appropriate RDMA operations that are handled by the RDMA-Capable Controller. The set of iSCSI data-type PDUs consists of SCSI Data-in PDUs and R2T PDUs.

iSCSI数据类型PDU定义为iSCSI PDU,它在iSCSI/iSER连接的全功能阶段,使对等iSCSI节点之间进行对远程iSCSI层透明的数据传输。iSCSI数据类型PDU在发送节点中的iSCSI层请求传输时,会导致数据在发送节点和接收节点的iSCSI层不参与的情况下传输。这是因为PDU本身没有按原样传递到接收节点中的iSCSI层。相反,数据传输操作被转换为适当的RDMA操作,由支持RDMA的控制器处理。iSCSI数据类型PDU集由PDU和R2T PDU中的SCSI数据组成。

If the invocation of the Operational Primitive by the iSCSI layer to request that the iSER layer process an iSCSI data-type PDU is qualified with Notify_Enable set, then upon completing the RDMA operation, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Data_Completion_Notify Operational Primitive qualified with ITT and SN. There is no data completion notification at the initiator since the RDMA operations are completely handled by the RDMA-Capable Controller at the initiator and the iSER layer at the initiator is not involved with the data transfer associated with iSCSI data-type PDUs.

如果iSCSI层调用操作原语请求iSER层处理iSCSI数据类型PDU符合Notify_Enable set,则在完成RDMA操作后,目标位置的iSER层必须通过调用ITT和SN限定的Data_Completion_notify Operational原语来通知目标位置的iSCSI层。由于RDMA操作完全由启动器上支持RDMA的控制器处理,并且启动器上的iSER层不涉及与iSCSI数据类型PDU关联的数据传输,因此启动器上没有数据完成通知。

If the invocation of the Operational Primitive by the iSCSI layer to request that the iSER layer process an iSCSI data-type PDU is qualified with Notify_Enable cleared, then upon completing the RDMA operation, the iSER layer at the target MUST NOT notify the iSCSI layer at the target and MUST NOT invoke the Data_Completion_Notify Operational Primitive.

如果iSCSI层调用操作原语以请求iSER层处理iSCSI数据类型PDU符合已清除Notify_Enable的条件,则在完成RDMA操作后,目标上的iSER层不得通知目标上的iSCSI层,也不得调用Data_Completion_notify Operational原语。

If an operation associated with an iSCSI data-type PDU fails for any reason, the contents of the Data Sink buffers associated with the operation are considered indeterminate.

如果与iSCSI数据类型PDU关联的操作因任何原因失败,则与该操作关联的数据接收器缓冲区的内容将被视为不确定。

7.2. iSCSI Control-Type PDU
7.2. iSCSI控制类型PDU

Any iSCSI PDU that is not an iSCSI data-type PDU and also not a SCSI Data-out PDU carrying solicited data is defined as an iSCSI control-type PDU. The iSCSI layer invokes the Send_Control Operational Primitive to request that the iSER layer process an iSCSI control-type PDU. iSCSI control-type PDUs are transferred using Send Message Types of RCaP. Specifically, note that SCSI Data-out PDUs carrying unsolicited data are defined as iSCSI control-type PDUs. See Section 7.3.4 on the treatment of SCSI Data-out PDUs.

任何不是iSCSI数据类型PDU,也不是承载请求数据的SCSI数据输出PDU的iSCSI PDU都被定义为iSCSI控制类型PDU。iSCSI层调用发送控制操作原语,请求iSER层处理iSCSI控制类型PDU。iSCSI控制类型PDU使用RCaP的发送消息类型传输。具体地说,请注意,携带未经请求数据的SCSI数据输出PDU被定义为iSCSI控制类型PDU。有关SCSI数据输出PDU的处理,请参见第7.3.4节。

When the iSER layer receives an iSCSI control-type PDU, it MUST notify the iSCSI layer by invoking the Control_Notify Operational Primitive qualified with the iSCSI control-type PDU.

当iSER层接收到iSCSI控制类型PDU时,它必须通过调用iSCSI控制类型PDU限定的control_notify Operational原语来通知iSCSI层。

7.3. iSCSI PDUs
7.3. iSCSI协议数据单元

This section describes the handling of each of the iSCSI PDU types by the iSER layer. The iSCSI layer requests that the iSER layer process the iSCSI PDU by invoking the appropriate Operational Primitive. A Connection_Handle MUST qualify each of these invocations. In addition, BHS and the optional AHS of the iSCSI PDU as defined in [RFC3720] MUST qualify each of the invocations. The qualifying Connection_Handle, the BHS, and the AHS are not explicitly listed in the subsequent sections.

本节介绍iSER层对每种iSCSI PDU类型的处理。iSCSI层请求iSER层通过调用适当的操作原语来处理iSCSI PDU。连接句柄必须限定每个调用。此外,[RFC3720]中定义的行李处理系统和iSCSI PDU的可选AHS必须限定每次调用。后续章节中未明确列出合格连接手柄、BHS和AHS。

7.3.1. SCSI Command
7.3.1. SCSI命令

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers (for SCSI Write or bidirectional command): ImmediateDataSize, UnsolicitedDataSize, DataDescriptorOut

PDU特定的限定符(用于SCSI写入或双向命令):立即tasize、未经请求的DataSize、DataDescriptorRout

PDU-specific qualifiers (for SCSI read or bidirectional command): DataDescriptorIn

PDU特定限定符(用于SCSI读取或双向命令):DataDescriptor

The iSER layer at the initiator MUST send the SCSI command in a SendSE Message to the target.

启动器上的iSER层必须以SendSE消息的形式将SCSI命令发送到目标。

For a SCSI Write or bidirectional command, the iSCSI layer at the initiator MUST invoke the Send_Control Operational Primitive as follows:

对于SCSI写入或双向命令,启动器处的iSCSI层必须调用Send_Control操作原语,如下所示:

* If there is immediate data to be transferred for the SCSI Write or bidirectional command, the qualifier ImmediateDataSize MUST be used to define the number of bytes of immediate unsolicited data to be sent with the Write or bidirectional command, and the qualifier DataDescriptorOut MUST be used to define the initiator's I/O Buffer containing the SCSI Write data.

* 如果SCSI写入或双向命令需要传输即时数据,则必须使用限定符ImmediatedTaskize来定义随写入或双向命令发送的即时未经请求数据的字节数,必须使用限定符DataDescriptorRout来定义包含SCSI写入数据的启动器的I/O缓冲区。

* If there is unsolicited data to be transferred for the SCSI Write or bidirectional command, the qualifier UnsolicitedDataSize MUST be used to define the number of bytes of immediate and non-immediate unsolicited data for the command. The iSCSI layer will issue one or more SCSI Data-out PDUs for the non-immediate unsolicited data. See Section 7.3.4 on SCSI Data-out.

* 如果SCSI写入或双向命令需要传输未经请求的数据,则必须使用限定符UnsolicitedDataSize来定义命令的即时和非即时未经请求数据的字节数。iSCSI层将为非即时未经请求的数据发出一个或多个SCSI数据输出PDU。有关SCSI数据输出,请参见第7.3.4节。

* If there is solicited data to be transferred for the SCSI write or bidirectional command, as indicated by the Expected Data Transfer Length in the SCSI Command PDU exceeding the value of UnsolicitedDataSize, the iSER layer at the initiator MUST do the following:

* 如果SCSI写入或双向命令需要传输请求的数据,如SCSI命令PDU中的预期数据传输长度超过UnsolicitedDataSize的值所示,则启动器的iSER层必须执行以下操作:

a. It MUST allocate a Write STag for the I/O Buffer defined by the qualifier DataDescriptorOut. The DataDescriptorOut describes the I/O buffer starting with the immediate unsolicited data (if any), followed by the non-immediate unsolicited data (if any) and solicited data. This means that the BufferOffset for the SCSI Data-out for this command is equal to the TO. This implies that a zero TO for this STag points to the beginning of this I/O Buffer.

a. 它必须为限定符DataDescriptorRout定义的I/O缓冲区分配写STag。DataDescriptorRout描述I/O缓冲区,首先是即时未请求的数据(如果有),然后是非即时未请求的数据(如果有)和请求的数据。这意味着此命令的SCSI数据输出的缓冲偏移量等于到。这意味着该STag的零到零表示该I/O缓冲区的开始。

b. It MUST establish a Local Mapping that associates the Initiator Task Tag (ITT) to the Write STag.

b. 它必须建立一个本地映射,将启动器任务标记(ITT)与写入STag相关联。

c. It MUST Advertise the Write STag to the target by sending it as the Write STag in the iSER header of the iSER Message (the payload of the SendSE Message of RCaP) containing the SCSI write or bidirectional command PDU. See Section 9.2 on iSER Header Format for the iSCSI Control-Type PDU.

c. 它必须将写入STag作为包含SCSI写入或双向命令PDU的iSER消息(RCaP的SendSE消息的有效负载)的iSER头中的写入STag发送给目标。有关iSCSI控制类型PDU,请参阅第9.2节iSER标头格式。

For a SCSI read or bidirectional command, the iSCSI layer at the initiator MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorIn, which defines the initiator's I/O

对于SCSI读取或双向命令,启动器的iSCSI层必须调用使用DataDescriptorIn限定的Send_Control操作原语,该原语定义启动器的I/O

Buffer for receiving the SCSI Read data. The iSER layer at the initiator MUST do the following:

用于接收SCSI读取数据的缓冲区。启动器上的iSER层必须执行以下操作:

a. It MUST allocate a Read STag for the I/O Buffer.

a. 它必须为I/O缓冲区分配一个读STag。

b. It MUST establish a Local Mapping that associates the Initiator Task Tag (ITT) to the Read STag.

b. 它必须建立一个本地映射,将启动器任务标记(ITT)与读取STag相关联。

c. It MUST Advertise the Read STag to the target by sending it as the Read STag in the iSER header of the iSER Message (the payload of the SendSE Message of RCaP) containing the SCSI read or bidirectional command PDU. See Section 9.2 on iSER Header Format for the iSCSI Control-Type PDU.

c. 它必须将读STag作为包含SCSI读取或双向命令PDU的iSER消息(RCaP的SendSE消息的有效负载)的iSER头中的读STag发送给目标。有关iSCSI控制类型PDU,请参阅第9.2节iSER标头格式。

If the amount of unsolicited data to be transferred in a SCSI command exceeds TargetRecvDataSegmentLength, then the iSCSI layer at the initiator MUST segment the data into multiple iSCSI control-type PDUs, with the data segment length in all PDUs generated except the last one having exactly the size TargetRecvDataSegmentLength. The data segment length of the last iSCSI control-type PDU carrying the unsolicited data can be up to TargetRecvDataSegmentLength.

如果要在SCSI命令中传输的未经请求的数据量超过TargetRecvDataSegmentLength,则启动器处的iSCSI层必须将数据分段为多个iSCSI控制类型PDU,生成的所有PDU中的数据段长度(最后一个PDU的大小正好与TargetRecvDataSegmentLength相同)。承载未经请求数据的最后一个iSCSI控制类型PDU的数据段长度可以达到TargetRecvDataSegmentLength。

When the iSER layer at the target receives the SCSI command, it MUST establish a Remote Mapping that associates the ITT to the Advertised Write STag and the Read STag if present in the iSER header. The Write STag is used by the iSER layer at the target in handling the data transfer associated with the R2T PDU(s) as described in Section 7.3.6. The Read STag is used in handling the SCSI Data-in PDU(s) from the iSCSI layer at the target as described in Section 7.3.5.

当目标的iSER层接收到SCSI命令时,它必须建立一个远程映射,将ITT与播发的写STag和读STag(如果iSER头中存在)相关联。如第7.3.6节所述,目标iSER层在处理与R2T PDU相关的数据传输时使用写STag。如第7.3.5节所述,Read STag用于处理来自目标iSCSI层的PDU中的SCSI数据。

7.3.2. SCSI Response
7.3.2. SCSI响应

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: DataDescriptorStatus

PDU特定限定符:DataDescriptorStatus

The iSCSI layer at the target MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorStatus, which defines the buffer containing the sense and response information. The iSCSI layer at the target MUST always return the SCSI status for a SCSI command in a separate SCSI Response PDU. "Phase collapse" for transferring SCSI status in a SCSI Data-in PDU MUST NOT be used. The iSER layer at the target sends the SCSI Response PDU according to the following rules:

目标位置的iSCSI层必须调用使用DataDescriptorStatus限定的Send_Control操作原语,该原语定义包含检测和响应信息的缓冲区。目标的iSCSI层必须始终在单独的SCSI响应PDU中返回SCSI命令的SCSI状态。不得使用用于传输PDU中SCSI数据中SCSI状态的“阶段折叠”。目标的iSER层根据以下规则发送SCSI响应PDU:

* If no STags are Advertised by the initiator in the iSER Message containing the SCSI command PDU, then the iSER layer at the target MUST send a SendSE Message containing the SCSI Response PDU.

* 如果启动器在包含SCSI命令PDU的iSER消息中未播发STAG,则目标的iSER层必须发送包含SCSI响应PDU的SendSE消息。

* If the initiator Advertised a Read STag in the iSER Message containing the SCSI Command PDU, then the iSER layer at the target MUST send a SendInvSE Message containing the SCSI Response PDU. The header of the SendInvSE Message MUST carry the Read STag to be invalidated at the initiator.

* 如果发起程序在包含SCSI命令PDU的iSER消息中公布了Read STag,则目标的iSER层必须发送包含SCSI响应PDU的SendInvSE消息。SendInvSE消息的标头必须包含要在启动器处失效的读取STag。

* If the initiator Advertised only the Write STag in the iSER Message containing the SCSI Command PDU, then the iSER layer at the target MUST send a SendInvSE Message containing the SCSI Response PDU. The header of the SendInvSE Message MUST carry the Write STag to be invalidated at the initiator.

* 如果启动器在包含SCSI命令PDU的iSER消息中仅公布写入STag,则目标的iSER层必须发送包含SCSI响应PDU的SendInvSE消息。SendInvSE消息的标头必须包含要在启动器处失效的写入STag。

When the iSCSI layer at the target invokes the Send_Control Operational Primitive to send the SCSI Response PDU, the iSER layer at the target MUST invalidate the Remote Mapping that associates the ITT to the Advertised STag(s) before transferring the SCSI Response PDU to the initiator.

当目标的iSCSI层调用Send_Control Operating Primitive发送SCSI响应PDU时,目标的iSER层必须在将SCSI响应PDU传输到启动器之前,使ITT与播发STag关联的远程映射失效。

Upon receiving the SendInvSE Message containing the SCSI Response PDU from the target, the RCaP layer at the initiator will invalidate the STag specified in the header. The iSER layer at the initiator MUST ensure that the correct STag is invalidated. If both the Read and the Write STags are Advertised earlier by the initiator, then the iSER layer at the initiator MUST explicitly invalidate the Write STag upon receiving the SendInvSE Message because the header of the SendInvSE Message can only carry one STag (in this case, the Read STag) to be invalidated.

从目标接收到包含SCSI响应PDU的SendInvSE消息后,发起方的RCaP层将使标头中指定的STag无效。启动器处的iSER层必须确保正确的STag无效。如果启动器较早地通告了读STag和写STag,则启动器的iSER层必须在收到SendInvSE消息时显式地使写STag无效,因为SendInvSE消息的头只能携带一个要无效的STag(在本例中为读STag)。

The iSER layer at the initiator MUST ensure the invalidation of the STag(s) used in a command before notifying the iSCSI layer at the initiator by invoking the Control_Notify Operational Primitive qualified with the SCSI Response. This precludes the possibility of using the STag(s) after the completion of the command, thereby causing data corruption.

启动器上的iSER层必须确保命令中使用的STag无效,然后通过调用SCSI响应限定的Control_Notify Operational原语通知启动器上的iSCSI层。这排除了在命令完成后使用STag的可能性,从而导致数据损坏。

When the iSER layer at the initiator receives the SendSE or the SendInvSE Message containing the SCSI Response PDU, it SHOULD invalidate the Local Mapping that associates the ITT to the local STag(s). The iSER layer MUST ensure that all local STag(s) associated with the ITT are invalidated before notifying the iSCSI layer of the SCSI Response PDU by invoking the Control_Notify Operational Primitive qualified with the SCSI Response PDU.

当启动器处的iSER层接收到包含SCSI响应PDU的SendSE或SendInvSE消息时,它应使将ITT与本地STag关联的本地映射失效。iSER层必须确保在通过调用SCSI响应PDU限定的Control_Notify Operational原语通知iSCSI层SCSI响应PDU之前,与ITT相关联的所有本地STag均无效。

7.3.3. Task Management Function Request/Response
7.3.3. 任务管理功能请求/响应

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers (for TMF Request): DataDescriptorOut, DataDescriptorIn

PDU特定限定符(用于TMF请求):DataDescriptorRout、DataDescriptorIn

The iSER layer MUST use a SendSE Message to send the Task Management Function Request/Response PDU.

iSER层必须使用SendSE消息来发送任务管理功能请求/响应PDU。

For the Task Management Function Request with the TASK REASSIGN function, the iSER layer at the initiator MUST do the following:

对于具有任务重新分配功能的任务管理功能请求,启动器的iSER层必须执行以下操作:

* It MUST use the ITT as specified in the Referenced Task Tag from the Task Management Function Request PDU to locate the existing STag(s), if any, in the Local Mapping(s) that associates the ITT to the local STag(s).

* 它必须使用任务管理功能请求PDU中引用的任务标记中指定的ITT,以在将ITT与本地STag关联的本地映射中定位现有STag(如有)。

* It MUST invalidate the existing STag(s), if any, and the Local Mapping(s) that associates the ITT to the local STag(s).

* 必须使现有STag(如有)和将ITT与本地STag关联的本地映射失效。

* It MUST allocate a Read STag for the I/O Buffer as defined by the qualifier DataDescriptorIn if the Send_Control Operational Primitive invocation is qualified with DataDescriptorIn.

* 如果发送控制操作原语调用使用DataDescriptorIn限定,则它必须为限定符DataDescriptorIn定义的I/O缓冲区分配读取STag。

* It MUST allocate a Write STag for the I/O Buffer as defined by the qualifier DataDescriptorOut if the Send_Control Operational Primitive invocation is qualified with DataDescriptorOut.

* 如果使用DataDescriptorRout限定发送控制操作原语调用,则必须为限定符DataDescriptorRout定义的I/O缓冲区分配写STag。

* If STags are allocated, it MUST establish a new Local Mapping(s) that associate the ITT to the allocated STag(s).

* 如果分配了STag,则必须建立新的本地映射,将ITT与分配的STag相关联。

* It MUST Advertise the STags, if allocated, to the target in the iSER header of the SendSE Message carrying the iSCSI PDU, as described in Section 9.2.

* 如第9.2节所述,它必须在承载iSCSI PDU的SendSE消息的iSER头中将STAG(如果已分配)通告给目标。

For the Task Management Function Request with the TASK REASSIGN function for a SCSI read or bidirectional command, the iSCSI layer at the initiator MUST set ExpDataSN to 0 since the data transfer and acknowledgements happen transparently to the iSCSI layer at the initiator. This provides the flexibility to the iSCSI layer at the target to request transmission of only the unacknowledged data as specified in [RFC3720].

对于具有SCSI读取或双向命令的任务重新分配功能的任务管理功能请求,启动器的iSCSI层必须将EXPDASN设置为0,因为数据传输和确认对启动器的iSCSI层是透明的。这为目标位置的iSCSI层提供了灵活性,可以根据[RFC3720]中的规定,仅请求传输未确认的数据。

When the iSER layer at the target receives the Task Management Function Request with the TASK REASSIGN function, it MUST do the following:

当目标的iSER层通过任务重新分配功能接收到任务管理功能请求时,它必须执行以下操作:

* It MUST use the ITT as specified in the Referenced Task Tag from the Task Management Function Request PDU to locate the mappings that associate the ITT to the Advertised STag(s) and the local STag(s), if any.

* 它必须使用任务管理功能请求PDU中引用的任务标记中指定的ITT,以定位将ITT与播发STag和本地STag(如有)关联的映射。

* It MUST invalidate the local STag(s), if any, associated with the ITT.

* 必须使与ITT相关的本地STag(如有)失效。

* It MUST replace the Advertised STag(s) in the Remote Mapping that associates the ITT to the Advertised STag(s) with the Write STag and the Read STag if present in the iSER header. The Write STag is used in the handling of the R2T PDU(s) from the iSCSI layer at the target as described in Section 7.3.6. The Read STag is used in the handling of the SCSI Data-in PDU(s) from the iSCSI layer at the target as described in Section 7.3.5.

* 它必须替换远程映射中的播发STag,远程映射将ITT与播发STag关联,如果iSER报头中存在写入STag和读取STag。如第7.3.6节所述,写入STag用于从目标iSCSI层处理R2T PDU。如第7.3.5节所述,Read STag用于处理来自目标iSCSI层的PDU中的SCSI数据。

7.3.4. SCSI Data-Out
7.3.4. SCSI数据输出

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: DataDescriptorOut

PDU特定限定符:DataDescriptorRout

The iSCSI layer at the initiator MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorOut, which defines the initiator's I/O Buffer containing unsolicited SCSI Write data.

启动器的iSCSI层必须调用使用DataDescriptorRout限定的Send_Control操作原语,该原语定义启动器的I/O缓冲区,其中包含未经请求的SCSI写入数据。

If the amount of unsolicited data to be transferred as SCSI Data-out exceeds TargetRecvDataSegmentLength, then the iSCSI layer at the initiator MUST segment the data into multiple iSCSI control-type PDUs, with the DataSegmentLength having the value of TargetRecvDataSegmentLength in all PDUs generated except the last one. The DataSegmentLength of the last iSCSI control-type PDU carrying the unsolicited data can be up to TargetRecvDataSegmentLength. The iSCSI layer at the target MUST perform the reassembly function for the unsolicited data.

如果要作为SCSI数据输出传输的未经请求的数据量超过了TargetRecvDataSegmentLength,则启动器处的iSCSI层必须将数据分段为多个iSCSI控制类型PDU,其中DataSegmentLength在生成的所有PDU中的值为TargetRecvDataSegmentLength,但最后一个PDU除外。承载未经请求的数据的最后一个iSCSI控制类型PDU的DataSegmentLength可以达到TargetRecvDataSegmentLength。目标位置的iSCSI层必须对未经请求的数据执行重新组装功能。

For unsolicited data, if the F bit is set to 0 in a SCSI Data-out PDU, the iSER layer at the initiator MUST use a Send Message to send the SCSI Data-out PDU. If the F bit is set to 1, the iSER layer at the initiator MUST use a SendSE Message to send the SCSI Data-out PDU.

对于未经请求的数据,如果SCSI数据输出PDU中的F位设置为0,则启动器处的iSER层必须使用发送消息将SCSI数据输出PDU。如果F位设置为1,则启动器处的iSER层必须使用SendSE消息将SCSI数据发送到PDU。

Note that for solicited data, the SCSI Data-out PDUs are not used since R2T PDUs are not delivered to the iSCSI layer at the initiator; instead, R2T PDUs are transformed by the iSER layer at the target into RDMA Read operations. (See Section 7.3.6.)

请注意,对于请求的数据,不会使用SCSI数据输出PDU,因为R2T PDU不会在启动器处传递到iSCSI层;相反,R2T PDU由目标的iSER层转换为RDMA读取操作。(见第7.3.6节。)

7.3.5. SCSI Data-In
7.3.5. 中的SCSI数据

Type: data-type PDU

类型:数据类型PDU

PDU-specific qualifiers: DataDescriptorIn

PDU特定限定符:DataDescriptorIn

When the iSCSI layer at the target is ready to return the SCSI Read data to the initiator, it MUST invoke the Put_Data Operational Primitive qualified with DataDescriptorIn, which defines the SCSI Data-in buffer. See Section 7.1 on the general requirement on the handling of iSCSI data-type PDUs. SCSI Data-in PDU(s) are used in SCSI Read data transfer as described in Section 9.5.2.

当目标的iSCSI层准备将SCSI读取数据返回到启动器时,它必须调用使用DataDescriptorIn限定的Put_数据操作原语,该原语定义缓冲区中的SCSI数据。有关iSCSI数据类型PDU处理的一般要求,请参见第7.1节。如第9.5.2节所述,PDU中的SCSI数据用于SCSI读取数据传输。

The iSER layer at the target MUST do the following for each invocation of the Put_Data Operational Primitive:

目标的iSER层必须为每次调用Put_数据操作原语执行以下操作:

1. It MUST use the ITT in the SCSI Data-in PDU to locate the remote Read STag in the Remote Mapping that associates the ITT to Advertised STag(s). The Remote Mapping was established earlier by the iSER layer at the target when the SCSI read command was received from the initiator.

1. 它必须在PDU中的SCSI数据中使用ITT,以在将ITT与播发STag关联的远程映射中定位远程读取STag。当从启动器接收到SCSI read命令时,iSER层在目标上较早地建立了远程映射。

2. It MUST generate and send an RDMA Write Message containing the read data to the initiator.

2. 它必须生成包含读取数据的RDMA写入消息并发送给启动器。

a. It MUST use the remote Read STag as the Data Sink STag of the RDMA Write Message.

a. 它必须使用远程读取STag作为RDMA写入消息的数据接收器STag。

b. It MUST use the Buffer Offset from the SCSI Data-in PDU as the Data Sink Tagged Offset of the RDMA Write Message.

b. 它必须使用PDU中SCSI数据的缓冲区偏移量作为RDMA写入消息的数据接收器标记偏移量。

c. It MUST use DataSegmentLength from the SCSI Data-in PDU to determine the amount of data to be sent in the RDMA Write Message.

c. 它必须使用PDU中SCSI数据的DataSegmentLength来确定RDMA写入消息中要发送的数据量。

3. It MUST associate DataSN and ITT from the SCSI Data-in PDU with the RDMA Write operation. If the Put_Data Operational Primitive invocation was qualified with Notify_Enable set, then when the iSER layer at the target receives a completion from the RCaP layer for the RDMA Write Message, the iSER layer at the target MUST notify the iSCSI layer by invoking the Data_Completion_Notify Operational Primitive qualified with DataSN and ITT. Conversely, if the Put_Data Operational Primitive invocation was qualified with Notify_Enable cleared, then the iSER layer at the target MUST NOT notify the iSCSI layer on completion and MUST NOT invoke the Data_Completion_Notify Operational Primitive.

3. 它必须将PDU中SCSI数据的DataSN和ITT与RDMA写入操作相关联。如果Put_数据操作原语调用通过Notify_Enable set限定,则当目标iSER层从RCaP层接收到RDMA写入消息的完成时,目标iSER层必须通过调用Data_completion_Notify操作原语(通过DataSN和ITT限定)来通知iSCSI层。相反,如果Put_数据操作原语调用在Notify_Enable清除时合格,则目标的iSER层不得在完成时通知iSCSI层,也不得调用Data_completion_Notify操作原语。

When the A-bit is set to 1 in the SCSI Data-in PDU, the iSER layer at the target MUST notify the iSCSI layer at the target when the data transfer is complete at the initiator. To perform this additional function, the iSER layer at the target can take advantage of the operational ErrorRecoveryLevel if previously disclosed by the iSCSI layer via an earlier invocation of the Notice_Key_Values Operational Primitive. There are two approaches that can be taken:

当PDU中的SCSI数据中的A位设置为1时,目标的iSER层必须在启动器的数据传输完成时通知目标的iSCSI层。要执行此附加功能,目标的iSER层可以利用operational ErrorRecoveryLevel(如果iSCSI层先前通过先前调用Notice_Key_Values操作原语公开)。可以采取两种方法:

1. If the iSER layer at the target knows that the operational ErrorRecoveryLevel is 2, or if the iSER layer at the target does not know the operational ErrorRecoveryLevel, then the iSER layer at the target MUST issue a zero-length RDMA Read Request Message following the RDMA Write Message. When the iSER layer at the target receives a completion for the RDMA Read Request Message from the RCaP layer, implying that the RDMA-Capable Controller at the initiator has completed processing the RDMA Write Message due to the completion ordering semantics of RCaP, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Data_Ack_Notify Operational Primitive qualified with ITT and DataSN (see Section 3.2.3).

1. 如果目标的iSER层知道operational ErrorRecoveryLevel为2,或者如果目标的iSER层不知道operational ErrorRecoveryLevel,则目标的iSER层必须在RDMA写入消息之后发出零长度RDMA读取请求消息。当目标的iSER层接收到来自RCaP层的RDMA读取请求消息的完成,这意味着由于RCaP的完成顺序语义,发起方的支持RDMA的控制器已经完成了对RDMA写入消息的处理,目标公司的iSER层必须通过调用ITT和DataSN限定的数据确认通知操作原语通知目标公司的iSCSI层(见第3.2.3节)。

2. If the iSER layer at the target knows that the operational ErrorRecoveryLevel is 1, then the iSER layer at the target MUST do one of the following:

2. 如果目标的iSER层知道operational ErrorRecoveryLevel为1,则目标的iSER层必须执行以下操作之一:

a. It MUST notify the iSCSI layer at the target by invoking the Data_Ack_Notify Operational Primitive qualified with ITT and DataSN (see Section 3.2.3) when it receives the local completion from the RCaP layer for the RDMA Write Message. This is allowed since digest errors do not occur in iSER (see Section 10.1.4.2) and a CRC error will cause the connection to be terminated and the task to be terminated anyway. The local RDMA Write completion from the RCaP layer guarantees that the RCaP layer will not access the I/O Buffer again to transfer the data associated with that RDMA Write operation.

a. 当接收到来自RCaP层的RDMA写入消息本地完成时,必须通过调用ITT和DataSN(见第3.2.3节)鉴定的Data_Ack_notify操作原语通知目标iSCSI层。这是允许的,因为iSER中不会出现摘要错误(请参见第10.1.4.2节),CRC错误将导致连接终止,任务也将终止。来自RCaP层的本地RDMA写入完成可确保RCaP层不会再次访问I/O缓冲区以传输与该RDMA写入操作相关的数据。

b. Alternatively, it MUST use the same procedure for handling the data transfer completion at the initiator as for ErrorRecoveryLevel 2.

b. 或者,它必须使用与ErrorRecoveryLevel 2相同的程序在启动器处处理数据传输完成。

Note that the iSCSI layer at the target cannot set the A-bit to 1 if the ErrorRecoveryLevel=0.

请注意,如果ErrorRecoveryLevel=0,则目标的iSCSI层无法将A位设置为1。

The SCSI status MUST always be returned in a separate SCSI Response PDU. The S bit in the SCSI Data-in PDU MUST always be set to 0. There MUST NOT be a "phase collapse" in the SCSI Data-in PDU.

SCSI状态必须始终在单独的SCSI响应PDU中返回。PDU中SCSI数据中的S位必须始终设置为0。PDU中的SCSI数据中不得存在“阶段崩溃”。

Since the RDMA Write Message only transfers the data portion of the SCSI Data-in PDU but not the control information in the header, such as ExpCmdSN, if timely updates of such information are crucial, the iSCSI layer at the initiator MAY issue NOP-Out PDUs to request that the iSCSI layer at the target respond with the information using NOP-In PDUs.

由于RDMA写入消息仅传输PDU中SCSI数据的数据部分,而不传输标头中的控制信息,如ExpCmdSN,如果及时更新此类信息至关重要,启动器处的iSCSI层可能会发出NOP Out PDU,以请求目标处的iSCSI层使用NOP In PDU响应信息。

7.3.6. Ready to Transfer (R2T)
7.3.6. 准备转移(R2T)

Type: data-type PDU

类型:数据类型PDU

PDU-specific qualifiers: DataDescriptorOut

PDU特定限定符:DataDescriptorRout

In order to send an R2T PDU, the iSCSI layer at the target MUST invoke the Get_Data Operational Primitive qualified with DataDescriptorOut, which defines the I/O Buffer for receiving the SCSI Write data from the initiator. See Section 7.1 on the general requirements on the handling of iSCSI data-type PDUs.

为了发送R2T PDU,目标位置的iSCSI层必须调用使用DataDescriptorRout限定的Get_数据操作原语,该原语定义用于从启动器接收SCSI写入数据的I/O缓冲区。有关iSCSI数据类型PDU处理的一般要求,请参见第7.1节。

The iSER layer at the target MUST do the following for each invocation of the Get_Data Operational Primitive:

目标的iSER层必须为每次调用Get_数据操作原语执行以下操作:

1. It MUST ensure a valid local STag for the I/O Buffer and a valid Local Mapping that associates the Initiator Task Tag (ITT) to the local STag. This may involve allocating a valid local STag and establishing a Local Mapping.

1. 它必须确保I/O缓冲区的有效本地STag,以及将启动器任务标记(ITT)关联到本地STag的有效本地映射。这可能涉及分配有效的本地STag和建立本地映射。

2. It MUST use the ITT in the R2T to locate the remote Write STag in the Remote Mapping that associates the ITT to Advertised STag(s). The Remote Mapping is established earlier by the iSER layer at the target when the iSER Message containing the Advertised Write STag and the SCSI Command PDU for a SCSI write or bidirectional command is received from the initiator.

2. 它必须使用R2T中的ITT在远程映射中定位远程写入STag,该映射将ITT与播发的STag相关联。当从启动器接收到包含播发写STag和SCSI写入或双向命令的SCSI命令PDU的iSER消息时,远程映射由目标的iSER层提前建立。

3. If the iSER-ORD value at the target is set to 0, the iSER layer at the target MUST terminate the connection and free up the resources associated with the connection (as described in Section 5.2.3) if it receives the R2T PDU from the iSCSI layer at the target. Upon termination of the connection, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Connection_Terminate_Notify Operational Primitive.

3. 如果目标的iSER ORD值设置为0,则如果目标的iSER层从目标的iSCSI层接收R2T PDU,则必须终止连接并释放与连接相关的资源(如第5.2.3节所述)。连接终止后,目标的iSER层必须通过调用connection_Terminate_notify操作原语通知目标的iSCSI层。

4. If the iSER-ORD value at the target is set to greater than 0, the iSER layer at the target MUST transform the R2T PDU into an RDMA Read Request Message. While transforming the R2T PDU, the iSER layer at the target MUST ensure that the number of outstanding RDMA Read Request Messages does not exceed the iSER-ORD value. To transform the R2T PDU, the iSER layer at the target:

4. 如果目标的iSER ORD值设置为大于0,则目标的iSER层必须将R2T PDU转换为RDMA读取请求消息。在转换R2T PDU时,目标的iSER层必须确保未完成RDMA读取请求消息的数量不超过iSER ORD值。要转换R2T PDU,目标上的iSER层:

a. MUST derive the local STag and local Tagged Offset from the DataDescriptorOut that qualified the Get_Data invocation.

a. 必须从限定Get_数据调用的DataDescriptorRout派生本地STag和本地标记偏移量。

b. MUST use the local STag as the Data Sink STag of the RDMA Read Request Message.

b. 必须使用本地STag作为RDMA读取请求消息的数据接收器STag。

c. MUST use the local Tagged Offset as the Data Sink Tagged Offset of the RDMA Read Request Message.

c. 必须使用本地标记的偏移量作为RDMA读取请求消息的数据接收器标记的偏移量。

d. MUST use the Desired Data Transfer Length from the R2T PDU as the RDMA Read Message Size of the RDMA Read Request Message.

d. 必须使用来自R2T PDU的所需数据传输长度作为RDMA读取请求消息的RDMA读取消息大小。

e. MUST use the remote Write STag as the Data Source STag of the RDMA Read Request Message.

e. 必须使用远程写入STag作为RDMA读取请求消息的数据源STag。

f. MUST use the Buffer Offset from the R2T PDU as the Data Source Tagged Offset of the RDMA Read Request Message.

f. 必须使用R2T PDU的缓冲区偏移量作为RDMA读取请求消息的数据源标记偏移量。

5. It MUST associate R2TSN and ITT from the R2T PDU with the RDMA Read operation. If the Get_Data Operational Primitive invocation is qualified with Notify_Enable set, then when the iSER layer at the target receives a completion from the RCaP layer for the RDMA Read operation, the iSER layer at the target MUST notify the iSCSI layer by invoking the Data_Completion_Notify Operational Primitive qualified with R2TSN and ITT. Conversely, if the Get_Data Operational Primitive invocation is qualified with Notify_Enable cleared, then the iSER layer at the target MUST NOT notify the iSCSI layer on completion and MUST NOT invoke the Data_Completion_Notify Operational Primitive.

5. 它必须将R2T PDU的R2TSN和ITT与RDMA读取操作相关联。如果Get_数据操作原语调用符合Notify_Enable set,则当目标iSER层从RCaP层接收到RDMA读取操作的完成时,目标iSER层必须通过调用符合R2TSN和ITT的Data_COMPLICATION_Notify操作原语来通知iSCSI层。相反,如果Get_Data OPERATION原语调用在Notify_Enable清除的情况下符合条件,则目标的iSER层不得在完成时通知iSCSI层,也不得调用Data_completion_Notify OPERATION原语。

When the RCaP layer at the initiator receives a valid RDMA Read Request Message, it will return an RDMA Read Response Message containing the solicited write data to the target. When the RCaP layer at target receives the RDMA Read Response Message from the initiator, it will place the solicited data in the I/O Buffer referenced by the Data Sink STag in the RDMA Read Response Message.

当启动器处的RCaP层接收到有效的RDMA读取请求消息时,它将向目标返回包含请求的写入数据的RDMA读取响应消息。当目标的RCaP层从发起方接收到RDMA读取响应消息时,它会将请求的数据放在RDMA读取响应消息中数据接收器STag引用的I/O缓冲区中。

Since the RDMA Read Request Message from the target does not transfer the control information in the R2T PDU, such as ExpCmdSN, if timely updates of such information are crucial, the iSCSI layer at the initiator MAY issue NOP-Out PDUs to request that the iSCSI layer at the target respond with the information using NOP-In PDUs.

由于来自目标的RDMA读取请求消息不会传输R2T PDU中的控制信息,例如ExpCmdSN,如果及时更新此类信息至关重要,则发起方的iSCSI层可能会发出NOP Out PDU,以请求目标的iSCSI层使用NOP in PDU响应信息。

Similarly, since the RDMA Read Response Message from the initiator only transfers the data but not the control information normally found in the SCSI Data-out PDU, such as ExpStatSN, if timely updates of such information are crucial, the iSCSI layer at the target MAY

类似地,由于来自启动器的RDMA读取响应消息仅传输SCSI数据输出PDU中通常存在的数据,而不传输控制信息,例如ExpStatSN,因此如果及时更新此类信息至关重要,则目标的iSCSI层可能会

issue NOP-In PDUs to request that the iSCSI layer at the initiator respond with the information using NOP-Out PDUs.

发出NOP In PDU请求启动器上的iSCSI层使用NOP Out PDU响应信息。

7.3.7. Asynchronous Message
7.3.7. 异步消息

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: DataDescriptorSense

PDU特定限定符:DataDescriptorSense

The iSCSI layer MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorSense, which defines the buffer containing the sense and iSCSI Event information. The iSER layer MUST use a SendSE Message to send the Asynchronous Message PDU.

iSCSI层必须调用使用DataDescriptorSense限定的Send_Control操作原语,该原语定义包含检测和iSCSI事件信息的缓冲区。iSER层必须使用SendSE消息来发送异步消息PDU。

7.3.8. Text Request and Text Response
7.3.8. 文本请求和文本响应

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: DataDescriptorTextOut (for Text Request), DataDescriptorIn (for Text Response)

PDU特定的限定符:DataDescriptorTextOut(用于文本请求)、DataDescriptorIn(用于文本响应)

The iSCSI layer MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorTextOut (or DataDescriptorIn), which defines the Text Request (or Text Response) buffer. The iSER layer MUST use SendSE Messages to send the Text Request (or Text Response PDUs).

iSCSI层必须调用使用DataDescriptorTextOut(或DataDescriptorIn)限定的发送控制操作原语,该原语定义文本请求(或文本响应)缓冲区。iSER层必须使用SendSE消息发送文本请求(或文本响应PDU)。

7.3.9. Login Request and Login Response
7.3.9. 登录请求和登录响应

During the login negotiation, the iSCSI layer interacts with the transport layer directly and the iSER layer is not involved. See Section 5.1 on iSCSI/iSER connection setup. If the underlying transport is TCP, the Login Request PDUs and the Login Response PDUs are exchanged when the connection between the initiator and the target is still in the byte stream mode.

在登录协商期间,iSCSI层直接与传输层交互,iSER层不参与。请参阅关于iSCSI/iSER连接设置的第5.1节。如果底层传输是TCP,则当启动器和目标之间的连接仍处于字节流模式时,将交换登录请求PDU和登录响应PDU。

The iSCSI layer MUST not send a Login Request (or a Login Response) PDU during the Full Feature Phase. A Login Request (or a Login Response) PDU, if used, MUST be treated as an iSCSI protocol error. The iSER layer MAY reject such a PDU from the iSCSI layer with an appropriate error code. If a Login Request PDU is received by the iSCSI layer at the target, it MUST respond with a Reject PDU with a reason code of "protocol error".

在完整功能阶段,iSCSI层不得发送登录请求(或登录响应)PDU。登录请求(或登录响应)PDU(如果使用)必须视为iSCSI协议错误。iSER层可以使用适当的错误代码从iSCSI层拒绝此类PDU。如果目标上的iSCSI层接收到登录请求PDU,则它必须以拒绝PDU响应,原因码为“协议错误”。

7.3.10. Logout Request and Logout Response
7.3.10. 注销请求和注销响应

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: None

PDU特定限定符:无

The iSER layer MUST use a SendSE Message to send the Logout Request or Logout Response PDU. Sections 5.2.1 and 5.2.2 describe the handling of the Logout Request and the Logout Response at the initiator and the target and the interactions between the initiator and the target to terminate a connection.

iSER层必须使用SendSE消息发送注销请求或注销响应PDU。第5.2.1节和第5.2.2节描述了注销请求和注销响应在发起方和目标方的处理,以及发起方和目标方之间终止连接的交互。

7.3.11. SNACK Request
7.3.11. 快餐请求

Since HeaderDigest and DataDigest must be negotiated to "None", there are no digest errors when the connection is in iSER-assisted mode. Also, since RCaP delivers all messages in the order they were sent, there are no sequence errors when the connection is in iSER-assisted mode. Therefore, the iSCSI layer MUST NOT send SNACK Request PDUs. A SNCAK Request PDU, if used, MUST be treated as an iSCSI protocol error. The iSER layer MAY reject such a PDU from the iSCSI layer with an appropriate error code. If a SNACK Request PDU is received by the iSCSI layer at the target, it MUST respond with a Reject PDU with a reason code of "protocol error".

由于HeaderDigest和DataDigest必须协商为“无”,因此当连接处于iSER辅助模式时,不会出现摘要错误。此外,由于RCaP按照发送顺序发送所有消息,因此当连接处于iSER辅助模式时,不会出现序列错误。因此,iSCSI层不能发送零食请求PDU。如果使用SNCAK请求PDU,则必须将其视为iSCSI协议错误。iSER层可以使用适当的错误代码从iSCSI层拒绝此类PDU。如果目标iSCSI层接收到零食请求PDU,它必须使用拒绝PDU进行响应,原因码为“协议错误”。

7.3.12. Reject
7.3.12. 拒绝

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: DataDescriptorReject

PDU特定限定符:DataDescriptorReject

The iSCSI layer MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorReject, which defines the Reject buffer. The iSER layer MUST use a SendSE Message to send the Reject PDU.

iSCSI层必须调用使用DataDescriptorReject限定的Send_Control操作原语,该原语定义拒绝缓冲区。iSER层必须使用SendSE消息发送拒绝PDU。

7.3.13. NOP-Out and NOP-In
7.3.13. 不进不出

Type: control-type PDU

类型:控制类型PDU

PDU-specific qualifiers: DataDescriptorNOPOut (for NOP-Out), DataDescriptorNOPIn (for NOP-In)

PDU特定限定符:DataDescriptorNOPOut(用于NOP Out)、DataDescriptorNOPIn(用于NOP In)

The iSCSI layer MUST invoke the Send_Control Operational Primitive qualified with DataDescriptorNOPOut (or DataDescriptorNOPIn), which defines the Ping (or Return Ping) data buffer. The iSER layer MUST use SendSE Messages to send the NOP-Out (or NOP-In) PDU.

iSCSI层必须调用使用DataDescriptorNoput(或DataDescriptorNOPIn)限定的Send_Control操作原语,该原语定义Ping(或Return Ping)数据缓冲区。iSER层必须使用SendSE消息发送NOP Out(或NOP In)PDU。

8. Flow Control and STag Management
8. 流量控制和STag管理
8.1. Flow Control for RDMA Send Message Types
8.1. RDMA发送消息类型的流控制

Send Message Types in RCaP are used by the iSER layer to transfer iSCSI control-type PDUs. Each Send Message Type in RCaP consumes an Untagged Buffer at the Data Sink. However, neither the RCaP layer nor the iSER layer provides an explicit flow control mechanism for the Send Message Types. Therefore, the iSER layer SHOULD provision enough Untagged buffers for handling incoming Send Message Types to prevent buffer exhaustion at the RCaP layer. If buffer exhaustion occurs, it may result in the termination of the connection.

iSER层使用RCaP中的发送消息类型传输iSCSI控制类型PDU。RCaP中的每种发送消息类型都在数据接收器上使用一个未标记的缓冲区。但是,RCaP层和iSER层都没有为发送消息类型提供显式的流控制机制。因此,iSER层应该提供足够的未标记缓冲区来处理传入的发送消息类型,以防止RCaP层的缓冲区耗尽。如果缓冲区耗尽,则可能导致连接终止。

An implementation may choose to satisfy the buffer requirement by using a common buffer pool shared across multiple connections, with usage limits on a per-connection basis and usage limits on the buffer pool itself. In such an implementation, exceeding the buffer usage limit for a connection or the buffer pool itself may trigger interventions from the iSER layer to replenish the buffer pool and/or to isolate the connection causing the problem.

实现可以选择通过使用跨多个连接共享的公共缓冲池来满足缓冲区需求,每个连接的使用限制和缓冲池本身的使用限制。在这种实现中,超过连接或缓冲池本身的缓冲区使用限制可能触发来自iSER层的干预,以补充缓冲池和/或隔离导致问题的连接。

iSER also provides the MaxOutstandingUnexpectedPDUs key to be used by the initiator and the target to declare the maximum number of outstanding "unexpected" control-type PDUs that it can receive. It is intended to allow the receiving side to determine the amount of buffer resources needed beyond the normal flow control mechanism available in iSCSI.

iSER还提供MaxOutstandingUnexpectedPDU密钥,供启动器和目标使用,以声明它可以接收的最大未完成“意外”控制类型PDU数。其目的是允许接收端确定超出iSCSI中可用的正常流量控制机制所需的缓冲区资源量。

The buffer resources required at both the initiator and the target as a result of control-type PDUs sent by the initiator is described in Section 8.1.1. The buffer resources required at both the initiator and target as a result of control-type PDUs sent by the target is described in Section 8.1.2.

由于启动器发送的控制类型PDU,启动器和目标所需的缓冲区资源在第8.1.1节中进行了描述。第8.1.2节描述了目标发送的控制类型PDU在启动器和目标上所需的缓冲区资源。

8.1.1. Flow Control for Control-Type PDUs from the Initiator
8.1.1. 来自启动器的控制类型PDU的流控制

The control-type PDUs that can be sent by an initiator to a target can be grouped into the following categories:

启动器可以向目标发送的控制类型PDU可分为以下类别:

1. Regulated: Control-type PDUs in this category are regulated by the iSCSI CmdSN window mechanism and the immediate flag is not set.

1. 受监管:此类别中的控制类型PDU由iSCSI CmdSN窗口机制监管,且未设置立即标志。

2. Unregulated but Expected: Control-type PDUs in this category are not regulated by the iSCSI CmdSN window mechanism but are expected by the target.

2. 不受监管但应为:此类别中的控制类型PDU不受iSCSI CmdSN窗口机制监管,但目标系统应为此类PDU。

3. Unregulated and Unexpected: Control-type PDUs in this category are not regulated by the iSCSI CmdSN window mechanism and are "unexpected" by the target.

3. 不受监管和意外:此类别中的控制类型PDU不受iSCSI CmdSN窗口机制的监管,并且由目标“意外”。

8.1.1.1. Control-Type PDUs from the Initiator in the Regulated Category
8.1.1.1. 来自受监管类别中启动器的控制类型PDU

Control-type PDUs that can be sent by the initiator in this category are regulated by the iSCSI CmdSN window mechanism and the immediate flag is not set.

可由此类启动器发送的控制类型PDU由iSCSI CmdSN窗口机制调节,且未设置立即标志。

The queuing capacity required of the iSCSI layer at the target is described in Section 3.2.2.1 of [RFC3720]. For each of the control-type PDUs that can be sent by the initiator in this category, the initiator MUST provision for the buffer resources required for the corresponding control-type PDU sent as a response from the target. The following is a list of the PDUs that can be sent by the initiator and the PDUs that are sent by the target in response:

[RFC3720]的第3.2.2.1节描述了目标位置iSCSI层所需的排队容量。对于此类别中的启动器可以发送的每个控制类型PDU,启动器必须为作为目标响应发送的相应控制类型PDU提供所需的缓冲区资源。以下是可由启动器发送的PDU和由目标发送的响应PDU的列表:

a. When an initiator sends a SCSI Command PDU, it expects a SCSI Response PDU from the target.

a. 当启动器发送SCSI命令PDU时,它期望目标发送SCSI响应PDU。

b. When the initiator sends a Task Management Function Request PDU, it expects a Task Management Function Response PDU from the target.

b. 当启动器发送任务管理功能请求PDU时,它期望目标发送任务管理功能响应PDU。

c. When the initiator sends a Text Request PDU, it expects a Text Response PDU from the target.

c. 当发起方发送文本请求PDU时,它期望来自目标的文本响应PDU。

d. When the initiator sends a Logout Request PDU, it expects a Logout Response PDU from the target.

d. 当发起方发送注销请求PDU时,它期望目标方发送注销响应PDU。

e. When the initiator sends a NOP-Out PDU as a ping request with ITT != 0xffffffff and TTT = 0xffffffff, it expects a NOP-In PDU from the target with the same ITT and TTT as in the ping request.

e. 当启动器发送NOP Out PDU作为带有ITT的ping请求时!=0xFFFFFF和TTT=0xffffffff,它期望目标PDU中的NOP与ping请求中的ITT和TTT相同。

The response from the target for any of the PDUs enumerated here may alternatively be in the form of a Reject PDU sent instead before the task is active, as described in Section 6.3 of [RFC3720].

如[RFC3720]第6.3节所述,目标对此处列举的任何PDU的响应也可以是在任务激活之前发送的拒绝PDU的形式。

8.1.1.2. Control-Type PDUs from the Initiator in the Unregulated but Expected Category

8.1.1.2. 来自发起程序的控制类型PDU属于不受监管但符合要求的类别

For the control-type PDUs in the Unregulated but Expected category, the amount of buffering resources required at the target can be predetermined. The following is a list of the PDUs in this category:

对于未监管但预期类别中的控制类型pdu,可以预定目标所需的缓冲资源量。以下是此类PDU的列表:

a. SCSI Data-out PDUs are used by the initiator to send unsolicited data. The amount of buffer resources required by the target can be determined using FirstBurstLength. Note that SCSI Data-out PDUs are not used for solicited data since the R2T PDU that is used for solicitation is transformed into RDMA Read operations by the iSER layer at the target. See Section 7.3.4.

a. SCSI数据输出PDU由启动器用于发送未经请求的数据。目标所需的缓冲区资源量可以使用FirstBurstLength确定。请注意,SCSI数据输出PDU不用于请求数据,因为用于请求的R2T PDU由目标iSER层转换为RDMA读取操作。见第7.3.4节。

b. A NOP-Out PDU with TTT != 0xffffffff is sent as a ping response by the initiator to the NOP-In PDU sent as a ping request by the target.

b. 带有TTT的NOP Out PDU!=0xFFFFFF由发起方作为ping响应发送给目标方作为ping请求发送的PDU中的NOP。

8.1.1.3. Control-Type PDUs from the Initiator in the Unregulated and Unexpected Category

8.1.1.3. 来自发起程序的控制类型PDU属于不受监管和意外类别

PDUs in the Unregulated and Unexpected category are PDUs with the immediate flag set. The number of PDUs in this category that can be sent by an initiator is controlled by the value of MaxOutstandingUnexpectedPDUs declared by the target (see Section 6.7). After a PDU in this category is sent by the initiator, it is outstanding until it is retired. At any time, the number of outstanding unexpected PDUs MUST not exceed the value of MaxOutstandingUnexpectedPDUs declared by the target.

未监管和意外类别中的PDU是设置了立即标志的PDU。发起方可以发送的此类PDU数量由目标方声明的MaxOutstandingUnexpectedPDU值控制(参见第6.7节)。发起方发送此类别的PDU后,该PDU将一直处于未完成状态,直至失效。任何时候,未完成的意外PDU的数量都不得超过目标声明的MaxOutstandingUnexpectedPDU的值。

The target uses the value of MaxOutstandingUnexpectedPDUs that it declared to determine the amount of buffer resources required for control-type PDUs in this category that can be sent by an initiator. For the initiator, for each of the control-type PDUs that can be sent in this category, the initiator MUST provision for the buffer resources if required for the corresponding control-type PDU that can be sent as a response from the target.

目标使用它声明的MaxOutstandingUnexpectedPDU的值来确定发起程序可以发送的此类控制类型PDU所需的缓冲区资源量。对于启动器,对于可在此类别中发送的每个控制类型PDU,如果需要,启动器必须为可作为目标响应发送的相应控制类型PDU提供缓冲区资源。

An outstanding PDU in this category is retired as follows. If the CmdSN of the PDU sent by the initiator in this category is x, the PDU is outstanding until the initiator sends a non-immediate control-type PDU on the same connection with CmdSN = y (where y is at least x) and the target responds with a control-type PDU on any connection where ExpCmdSN is at least y+1.

该类别中的一个优秀PDU退役如下。如果此类别中的启动器发送的PDU的CmdSN为x,则PDU处于未完成状态,直到启动器在CmdSN=y(其中y至少为x)的同一连接上发送非即时控制类型PDU,并且目标在ExpCmdSN至少为y+1的任何连接上使用控制类型PDU进行响应。

When the number of outstanding unexpected control-type PDUs equals MaxOutstandingUnexpectedPDUs, the iSCSI layer at the initiator MUST NOT generate any unexpected PDUs that otherwise it would have generated, even if it is intended for immediate delivery.

当未完成的意外控制类型PDU的数量等于MaxOutstandingUnexpectedPDU时,启动器处的iSCSI层不得生成任何未完成的PDU,否则它将生成任何未完成的PDU,即使该PDU旨在立即交付。

8.1.2. Flow Control for Control-Type PDUs from the Target
8.1.2. 来自目标的控制类型PDU的流控制

Control-type PDUs that can be sent by a target and are expected by the initiator are listed in the Regulated category (see Section 8.1.1.1).

可由目标发送且发起者预期的控制型PDU列在规定类别中(见第8.1.1.1节)。

For the control-type PDUs that can be sent by a target and are unexpected by the initiator, the number is controlled by MaxOutstandingUnexpectedPDUs declared by the initiator (see Section 6.7). After a PDU in this category is sent by a target, it is outstanding until it is retired. At any time, the number of outstanding unexpected PDUs MUST not exceed the value of MaxOutstandingUnexpectedPDUs declared by the initiator. The initiator uses the value of MaxOutstandingUnexpectedPDUs that it declared to determine the amount of buffer resources required for control-type PDUs in this category that can be sent by a target. The following is a list of the PDUs in this category and the conditions for retiring the outstanding PDU:

对于可由目标发送且发起者未预料到的控制类型PDU,其数量由发起者声明的MaxOutstandingUnexpectedPDU控制(参见第6.7节)。目标发送此类别的PDU后,该PDU将一直处于未完成状态,直到其退役。任何时候,未完成的意外PDU的数量都不得超过启动器声明的MaxOutstandingUnexpectedPDU的值。启动器使用其声明的MaxOutstandingUnexpectedPDU值来确定目标可以发送的此类控制类型PDU所需的缓冲区资源量。以下是此类PDU的列表,以及退役未完成PDU的条件:

a. For an Asynchronous Message PDU with StatSN = x, the PDU is outstanding until the initiator sends a control-type PDU with ExpStatSN set to at least x+1.

a. 对于StatSN=x的异步消息PDU,在启动器发送ExpStatSN设置为至少x+1的控制类型PDU之前,PDU是未完成的。

b. For a Reject PDU with StatSN = x that is sent after a task is active, the PDU is outstanding until the initiator sends a control-type PDU with ExpStatSN set to at least x+1.

b. 对于在任务激活后发送的StatSN=x的拒绝PDU,PDU处于未完成状态,直到启动器发送ExpStatSN设置为至少x+1的控制类型PDU。

c. For a NOP-In PDU with ITT = 0xffffffff and StatSN = x, the PDU is outstanding until the initiator responds with a control-type PDU on the same connection where ExpStatSN is at least x+1. But if the NOP-In PDU is sent as a ping request with TTT != 0xffffffff, the PDU can also be retired when the initiator sends a NOP-Out PDU with the same ITT and TTT as in the ping request. Note that when a target sends a NOP-In PDU as a ping request, it must provision a buffer for the NOP-Out PDU sent as a ping response from the initiator.

c. 对于ITT=0xFFFFFF且StatSN=x的PDU中的NOP,PDU是未完成的,直到启动器在同一连接上使用控制类型PDU进行响应,其中ExpStatSN至少为x+1。但是如果PDU中的NOP作为带有TTT的ping请求发送0xFFFFFF,当启动器发送NOP Out PDU时,PDU也可以失效,其ITT和TTT与ping请求中的相同。请注意,当目标以ping请求的形式发送NOP-In-PDU时,它必须为作为ping响应从启动器发送的NOP-Out PDU提供缓冲区。

When the number of outstanding unexpected control-type PDUs equals MaxOutstandingUnexpectedPDUs, the iSCSI layer at the target MUST NOT generate any unexpected PDUs that otherwise it would have generated, even if its intent is to indicate an iSCSI error condition (e.g., Asynchronous Message, Reject). Task timeouts, as in the initiator waiting for a command completion or other connection and session level exceptions, will ensure that correct operational behavior will result in these cases despite not generating the PDU. This rule overrides any other requirements elsewhere that require that a Reject PDU MUST be sent.

当未完成的意外控制类型PDU的数量等于MaxOutstandingUnexpectedPDU时,目标上的iSCSI层不得生成其本来会生成的任何意外PDU,即使其目的是指示iSCSI错误情况(例如,异步消息、拒绝)。任务超时,如启动器等待命令完成或其他连接和会话级别异常,将确保在这些情况下,即使不生成PDU,也会导致正确的操作行为。此规则覆盖其他任何要求必须发送拒绝PDU的要求。

(Implementation note: A SCSI task timeout and recovery can be a lengthy process and hence SHOULD be avoided by proper provisioning of resources.)

(实施说明:SCSI任务超时和恢复可能是一个漫长的过程,因此应通过适当的资源调配来避免。)

(Implementation note: To ensure that the initiator has a means to inform the target that outstanding PDUs have been retired, the target should reserve the last unexpected control-type PDU allowable by the value of MaxOutstandingUnexpectedPDUs declared by the initiator for sending a NOP-In ping request with TTT != 0xffffffff to allow the initiator to return the NOP-Out ping response with the current ExpStatSN.)

(实施说明:为确保发起方有办法通知目标方未完成的PDU已失效,目标方应保留发起方声明的MaxOutstandingUnexpectedPDU值允许的最后一个意外控制类型PDU,用于发送TTT!=0xffffffff的NOP In ping请求,以允许发起方使用当前ExpStatSN返回NOP Out ping响应。)

8.2. Flow Control for RDMA Read Resources
8.2. RDMA读取资源的流控制

The total number of RDMA Read operations that can be active simultaneously on an iSCSI/iSER connection depends on the amount of resources allocated as declared in the iSER Hello exchange described in Section 5.1.3. Exceeding the number of RDMA Read operations allowed on a connection will result in the connection being terminated by the RCaP layer. The iSER layer at the target maintains the iSER-ORD to keep track of the maximum number of RDMA Read Requests that can be issued by the iSER layer on a particular RCaP Stream.

iSCSI/iSER连接上可同时处于活动状态的RDMA读取操作总数取决于在第5.1.3节所述的iSER Hello exchange中声明的分配资源量。超过连接上允许的RDMA读取操作数将导致连接被RCaP层终止。目标的iSER层维护iSER ORD,以跟踪iSER层在特定RCaP流上可以发出的最大RDMA读取请求数。

During connection setup (see Section 5.1), iSER-IRD is known at the initiator and iSER-ORD is known at the target after the iSER layers at the initiator and the target have respectively allocated the connection resources necessary to support RCaP, as directed by the Allocate_Connection_Resources Operational Primitive from the iSCSI layer before the end of the iSCSI Login Phase. In the Full Feature Phase, the first message sent by the initiator is the iSER Hello Message (see Section 9.3), which contains the value of iSER-IRD. In response to the iSER Hello Message, the target sends the iSER HelloReply Message (see Section 9.4), which contains the value of iSER-ORD. The iSER layer at both the initiator and the target MAY adjust (lower) the resources associated with iSER-IRD and iSER-ORD respectively to match the iSER-ORD value declared in the HelloReply Message. The iSER layer at the target MUST flow control the RDMA Read Request Messages to not exceed the iSER-ORD value at the target.

在连接设置期间(参见第5.1节),在启动器和目标的iSER层分别分配了支持RCaP所需的连接资源后,启动器和目标的iSER IRD和iSER ORD是已知的,在iSCSI登录阶段结束之前,按照iSCSI层的Allocate_Connection_Resources操作原语的指示。在完整功能阶段,发起者发送的第一条消息是iSER Hello消息(参见第9.3节),其中包含iSER IRD的值。作为对iSER Hello消息的响应,目标发送iSER HelloReply消息(参见第9.4节),其中包含iSER ORD的值。发起方和目标方的iSER层可以分别调整(降低)与iSER IRD和iSER ORD相关联的资源,以匹配HelloReply消息中声明的iSER ORD值。目标上的iSER层必须控制RDMA读取请求消息流,使其不超过目标上的iSER ORD值。

8.3. STag Management
8.3. 雄鹿管理

An STag, as defined in [RDMAP], is an identifier of a Tagged Buffer used in an RDMA operation. The allocation and the subsequent invalidation of the STags are specified in this document if the STags are exposed on the wire by being Advertised in the iSER header or declared in the header of an RCaP Message.

如[RDMAP]中所定义,STag是RDMA操作中使用的标记缓冲区的标识符。如果STAG通过在iSER报头中公布或在RCaP消息报头中声明而在线路上公开,则本文件规定了STAG的分配和随后的失效。

8.3.1. Allocation of STags
8.3.1. 牡鹿的分配

When the iSCSI layer at the initiator invokes the Send_Control Operational Primitive to request that the iSER layer at the initiator process a SCSI command, zero, one, or two STags may be allocated by the iSER layer. See Section 7.3.1 for details. The number of STags allocated depends on whether the command is unidirectional or bidirectional and whether or not solicited write data transfer is involved.

当启动器上的iSCSI层调用Send_Control操作原语请求启动器上的iSER层处理SCSI命令时,iSER层可以分配零、一或两个stag。详见第7.3.1节。分配的stag数量取决于命令是单向的还是双向的,以及是否涉及请求的写数据传输。

When the iSCSI layer at the initiator invokes the Send_Control Operational Primitive to request that the iSER layer at the initiator process a Task Management Function Request with the TASK REASSIGN function, besides allocating zero, one, or two STags, the iSER layer MUST invalidate the existing STags, if any, associated with the ITT. See Section 7.3.3 for details.

当启动器上的iSCSI层调用Send_Control操作原语请求启动器上的iSER层使用任务重新分配功能处理任务管理功能请求时,除了分配零、一或两个stag外,iSER层还必须使与ITT相关的现有stag(如果有)失效。详见第7.3.3节。

The iSER layer at the target allocates a local Data Sink STag when the iSCSI layer at the target invokes the Get_Data Operational Primitive to request that the iSER layer process an R2T PDU. See Section 7.3.6 for details.

当目标的iSCSI层调用Get_数据操作原语请求iSER层处理R2T PDU时,目标的iSER层分配本地数据接收器STag。详见第7.3.6节。

8.3.2. Invalidation of STags
8.3.2. 雄鹿无效

The invalidation of the STags at the initiator at the completion of a unidirectional or bidirectional command when the associated SCSI Response PDU is sent by the target is described in Section 7.3.2.

第7.3.2节描述了当目标发送相关SCSI响应PDU时,在完成单向或双向命令时,启动器上的STAG失效。

When a unidirectional or bidirectional command concludes without the associated SCSI Response PDU being sent by the target, the iSCSI layer at the initiator MUST request that the iSER layer at the initiator invalidate the STags by invoking the Deallocate_Task_Resources Operational Primitive qualified with ITT. In response, the iSER layer at the initiator MUST locate the STag(s) (if any) in the Local Mapping that associates the ITT to the local STag(s). The iSER layer at the initiator MUST invalidate the STag(s) (if any) and the Local Mapping.

当单向或双向命令结束时,目标没有发送相关的SCSI响应PDU,则启动器的iSCSI层必须请求启动器的iSER层通过调用ITT限定的解除分配任务资源操作原语使STAG无效。作为响应,启动器处的iSER层必须在将ITT与本地STag关联的本地映射中定位STag(如果有)。启动器处的iSER层必须使STag(如果有)和本地映射无效。

For an RDMA Read operation used to realize a SCSI Write data transfer, the iSER layer at the target SHOULD invalidate the Data Sink STag at the conclusion of the RDMA Read operation referencing the Data Sink STag (to permit the immediate reuse of buffer resources).

对于用于实现SCSI写入数据传输的RDMA读取操作,目标的iSER层应在引用数据接收器STag的RDMA读取操作结束时使数据接收器STag失效(以允许立即重用缓冲区资源)。

For an RDMA Write operation used to realize a SCSI Read data transfer, the Data Source STag at the target is not declared to the initiator and is not exposed on the wire. Invalidation of the STag is thus not specified.

对于用于实现SCSI读取数据传输的RDMA写入操作,目标上的数据源STag不向启动器声明,也不在线路上公开。因此,未规定STag的失效。

When a unidirectional or bidirectional command concludes without the associated SCSI Response PDU being sent by the target, the iSCSI layer at the target MUST request that the iSER layer at the target invalidate the STags by invoking the Deallocate_Task_Resources Operational Primitive qualified with ITT. In response, the iSER layer at the target MUST locate the local STag(s) (if any) in the Local Mapping that associates the ITT to the local STag(s). The iSER layer at the target MUST invalidate the local STag(s) (if any) and the mapping.

当单向或双向命令结束时,目标系统未发送相关的SCSI响应PDU,目标系统的iSCSI层必须请求目标系统的iSER层调用ITT限定的解除分配任务资源操作原语,使STAG失效。作为响应,目标的iSER层必须在将ITT与本地STag关联的本地映射中定位本地STag(如果有)。目标的iSER层必须使本地STag(如果有)和映射无效。

9. iSER Control and Data Transfer
9. iSER控制和数据传输

For iSCSI data-type PDUs (see Section 7.1), the iSER layer uses RDMA Read and RDMA Write operations to transfer the solicited data. For iSCSI control-type PDUs (see Section 7.2), the iSER layer uses Send Message Types of RCaP.

对于iSCSI数据类型PDU(请参阅第7.1节),iSER层使用RDMA读取和RDMA写入操作来传输请求的数据。对于iSCSI控制类型PDU(参见第7.2节),iSER层使用RCaP的发送消息类型。

9.1. iSER Header Format
9.1. iSER头格式

An iSER header MUST be present in every Send Message Type of RCaP. The iSER header is located in the first 12 bytes of the message payload of the Send Message Type of RCaP, as shown in Figure 2.

每个RCaP发送消息类型中都必须存在iSER头。iSER报头位于RCaP发送消息类型的消息有效负载的前12个字节中,如图2所示。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode|                  Opcode Specific Fields               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Opcode Specific Fields                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Opcode Specific Fields                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode|                  Opcode Specific Fields               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Opcode Specific Fields                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Opcode Specific Fields                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 2. iSER Header Format

图2。iSER头格式

Opcode - Operation Code: 4 bits

操作码-操作码:4位

The Opcode field identifies the type of iSER Messages:

操作码字段标识iSER消息的类型:

           0001b = iSCSI control-type PDU
        
           0001b = iSCSI control-type PDU
        
           0010b = iSER Hello Message
        
           0010b = iSER Hello Message
        
           0011b = iSER HelloReply Message
        
           0011b = iSER HelloReply Message
        

All other opcodes are reserved.

保留所有其他操作码。

9.2. iSER Header Format for the iSCSI Control-Type PDU
9.2. iSCSI控制类型PDU的iSER标头格式

The iSER layer uses Send Message Types of RCaP to transfer iSCSI control-type PDUs (see Section 7.2). The message payload of each of the Send Message Types of RCaP used for transferring an iSER Message contains an iSER Header followed by an iSCSI control-type PDU.

iSER层使用RCaP的发送消息类型来传输iSCSI控制类型PDU(参见第7.2节)。用于传输iSER消息的每个RCaP发送消息类型的消息有效负载包含iSER头,后跟iSCSI控制类型PDU。

The iSER header in a Send Message Type of RCaP carrying an iSCSI control-type PDU MUST have the format as described in Figure 3.

带有iSCSI控制类型PDU的RCaP发送消息类型中的iSER头必须具有图3中所述的格式。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       |W|R|                                                   |
      | 0001b |S|S|                  Reserved                         |
      |       |V|V|                                                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Write STag (or N/A)                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Read STag (or N/A)                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       |W|R|                                                   |
      | 0001b |S|S|                  Reserved                         |
      |       |V|V|                                                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Write STag (or N/A)                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Read STag (or N/A)                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 3. iSER Header Format for iSCSI Control-Type PDU

图3。iSCSI控制类型PDU的iSER标头格式

WSV - Write STag Valid flag: 1 bit

WSV-写入STag有效标志:1位

This flag indicates the validity of the Write STag field of the iSER Header. If set to one, the Write STag field in this iSER Header is valid. If set to zero, the Write STag field in this iSER Header MUST be ignored at the receiver. The Write STag Valid flag is set to one when there is solicited data to be transferred for a SCSI write or bidirectional command, or when there are non-immediate unsolicited and solicited data to be transferred for the referenced task specified in a Task Management Function Request with the TASK REASSIGN function.

此标志指示iSER头的Write STag字段的有效性。如果设置为1,则此iSER头中的Write STag字段有效。如果设置为零,则必须在接收器处忽略此iSER头中的Write STag字段。当SCSI写入或双向命令需要传输请求数据时,或当任务管理功能请求中使用任务重新分配功能指定的引用任务需要传输非即时非请求和请求数据时,Write STag Valid标志设置为1。

RSV - Read STag Valid flag: 1 bit

RSV-读取STag有效标志:1位

This flag indicates the validity of the Read STag field of the iSER Header. If set to one, the Read STag field in this iSER Header is valid. If set to zero, the Read STag field in this iSER Header MUST be ignored at the receiver. The Read STag Valid flag is set to one for a SCSI read or bidirectional command, or for a Task Management Function Request with the TASK REASSIGN function.

此标志指示iSER头的读取STag字段的有效性。如果设置为1,则此iSER标头中的Read STag字段有效。如果设置为零,则必须在接收器处忽略此iSER头中的Read STag字段。对于SCSI读取或双向命令,或者对于具有任务重新分配功能的任务管理功能请求,Read STag Valid标志设置为1。

Write STag - Write Steering Tag: 32 bits

写入STag-写入转向标记:32位

This field contains the Write STag when the Write STag Valid flag is set to one. For a SCSI write or bidirectional command, the Write STag is used to Advertise the initiator's I/O Buffer containing the solicited data. For a Task Management Function Request with the TASK REASSIGN function, the Write STag is used to Advertise the initiator's I/O Buffer containing the non-immediate unsolicited data and solicited data. This Write STag is used as the Data Source STag in the resultant RDMA Read operation(s). When the Write STag Valid flag is set to zero, this field MUST be set to zero.

当Write STag Valid标志设置为1时,此字段包含Write STag。对于SCSI写入或双向命令,write STag用于公布包含请求数据的启动器的I/O缓冲区。对于具有任务重新分配功能的任务管理功能请求,Write STag用于公布启动器的I/O缓冲区,其中包含非即时非请求数据和请求数据。此写入STag用作结果RDMA读取操作中的数据源STag。当Write STag Valid标志设置为零时,此字段必须设置为零。

Read STag - Read Steering Tag: 32 bits

读取STag-读取转向标签:32位

This field contains the Read STag when the Read STag Valid flag is set to one. The Read STag is used to Advertise the initiator's Read I/O Buffer of a SCSI read or bidirectional command, or of a Task Management Function Request with the TASK REASSIGN function. This Read STag is used as the Data Sink STag in the resultant RDMA Write operation(s). When the Read STag Valid flag is zero, this field MUST be set to zero.

当Read STag Valid标志设置为1时,此字段包含Read STag。Read STag用于通告启动器的SCSI读取或双向命令的读取I/O缓冲区,或具有任务重新分配功能的任务管理功能请求的读取I/O缓冲区。此读取STag用作结果RDMA写入操作中的数据接收器STag。当Read STag Valid标志为零时,此字段必须设置为零。

Reserved:

保留:

Reserved fields MUST be set to zero on transmit and MUST be ignored on reception.

传输时必须将保留字段设置为零,接收时必须忽略保留字段。

9.3. iSER Header Format for the iSER Hello Message
9.3. iSER Hello消息的iSER头格式

An iSER Hello Message MUST only contain the iSER header, which MUST have the format as described in Figure 4. The iSER Hello Message is the first iSER Message sent on the RCaP Stream from the iSER layer at the initiator to the iSER layer at the target.

iSER Hello消息必须只包含iSER头,其格式必须如图4所示。iSER Hello消息是在RCaP流上从发起方的iSER层发送到目标方的iSER层的第一条iSER消息。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       |       |       |       |                               |
      | 0010b | Rsvd  | MaxVer| MinVer|           iSER-IRD            |
      |       |       |       |       |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       |       |       |       |                               |
      | 0010b | Rsvd  | MaxVer| MinVer|           iSER-IRD            |
      |       |       |       |       |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 4. iSER Header Format for iSER Hello Message

图4。iSER Hello消息的iSER头格式

MaxVer - Maximum Version: 4 bits

MaxVer-最大版本:4位

This field specifies the maximum version of the iSER protocol supported. It MUST be set to one to indicate the version of the specification described in this document.

此字段指定支持的iSER协议的最大版本。必须将其设置为1,以指示本文档中描述的规范版本。

MinVer - Minimum Version: 4 bits

MinVer-最小版本:4位

This field specifies the minimum version of the iSER protocol supported. It MUST be set to one to indicate the version of the specification described in this document.

此字段指定支持的iSER协议的最低版本。必须将其设置为1,以指示本文档中描述的规范版本。

iSER-IRD: 16 bits

iSER IRD:16位

This field contains the value of the iSER-IRD at the initiator.

此字段包含启动器上iSER IRD的值。

Reserved (Rsvd):

预留(Rsvd):

Reserved fields MUST be set to zero on transmit, and MUST be ignored on reception.

传输时必须将保留字段设置为零,接收时必须忽略保留字段。

9.4. iSER Header Format for the iSER HelloReply Message
9.4. iSER HelloReply消息的iSER头格式

An iSER HelloReply Message MUST only contain the iSER header which MUST have the format as described in Figure 5. The iSER HelloReply Message is the first iSER Message sent on the RCaP Stream from the iSER layer at the target to the iSER layer at the initiator.

iSER HelloReply消息必须只包含iSER头,该头必须具有图5中所述的格式。iSER HelloReply消息是在RCaP流上从目标的iSER层发送到启动器的iSER层的第一条iSER消息。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       |     |R|       |       |                               |
      | 0011b |Rsvd |E| MaxVer| CurVer|           iSER-ORD            |
      |       |     |J|       |       |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       |     |R|       |       |                               |
      | 0011b |Rsvd |E| MaxVer| CurVer|           iSER-ORD            |
      |       |     |J|       |       |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Reserved                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 5. iSER Header Format for iSER HelloReply Message

图5。iSER HelloReply消息的iSER头格式

REJ - Reject flag: 1 bit

REJ-拒绝标志:1位

This flag indicates whether the target is rejecting this connection. If set to one, the target is rejecting the connection.

此标志指示目标是否拒绝此连接。如果设置为1,则目标拒绝连接。

MaxVer - Maximum Version: 4 bits

MaxVer-最大版本:4位

This field specifies the maximum version of the iSER protocol supported. It MUST be set to one to indicate the version of the specification described in this document.

此字段指定支持的iSER协议的最大版本。必须将其设置为1,以指示本文档中描述的规范版本。

CurVer - Current Version: 4 bits

CurVer-当前版本:4位

This field specifies the current version of the iSER protocol supported. It MUST be set to one to indicate the version of the specification described in this document.

此字段指定支持的iSER协议的当前版本。必须将其设置为1,以指示本文档中描述的规范版本。

iSER-ORD: 16 bits

iSER ORD:16位

This field contains the value of the iSER-ORD at the target.

此字段包含目标的iSER ORD值。

Reserved (Rsvd):

预留(Rsvd):

Reserved fields MUST be set to zero on transmit, and MUST be ignored on reception.

传输时必须将保留字段设置为零,接收时必须忽略保留字段。

9.5. SCSI Data Transfer Operations
9.5. SCSI数据传输操作

The iSER layer at the initiator and the iSER layer at the target handle each SCSI Write, SCSI Read, and bidirectional operation as described below.

启动器的iSER层和目标的iSER层处理每个SCSI写入、SCSI读取和双向操作,如下所述。

9.5.1. SCSI Write Operation
9.5.1. SCSI写操作

The iSCSI layer at the initiator MUST invoke the Send_Control Operational Primitive to request that the iSER layer at the initiator send the SCSI write command. The iSER layer at the initiator MUST request that the RCaP layer transmit a SendSE Message with the message payload consisting of the iSER header followed by the SCSI Command PDU and immediate data (if any). If there is solicited data, the iSER layer MUST Advertise the Write STag in the iSER header of the SendSE Message, as described in Section 9.2. Upon receiving the SendSE Message, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Control_Notify Operational Primitive qualified with the SCSI Command PDU. See Section 7.3.1 for details on the handling of the SCSI write command.

启动器的iSCSI层必须调用Send_Control操作原语,以请求启动器的iSER层发送SCSI写入命令。启动器处的iSER层必须请求RCaP层传输SendSE消息,消息有效负载包括iSER头,后跟SCSI命令PDU和即时数据(如果有)。如第9.2节所述,如果存在请求的数据,iSER层必须在SendSE消息的iSER报头中公布写入STag。接收到SendSE消息后,目标服务器的iSER层必须通过调用SCSI命令PDU限定的Control_notify Operational原语来通知目标服务器的iSCSI层。有关SCSI写入命令处理的详细信息,请参阅第7.3.1节。

For the non-immediate unsolicited data, the iSCSI layer at the initiator MUST invoke a Send_Control Operational Primitive qualified with the SCSI Data-out PDU. Upon receiving each Send or SendSE Message containing the non-immediate unsolicited data, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Control_Notify Operational Primitive qualified with the SCSI

对于非即时未经请求的数据,启动器处的iSCSI层必须调用使用SCSI数据输出PDU限定的发送控制操作原语。在接收到包含非即时非请求数据的每个发送或发送消息后,目标的iSER层必须通过调用SCSI限定的Control_notify Operational原语通知目标的iSCSI层

Data-out PDU. See Section 7.3.4 for details on the handling of the SCSI Data-out PDU.

数据输出PDU。有关SCSI数据输出PDU处理的详细信息,请参阅第7.3.4节。

For the solicited data, when the iSCSI layer at the target has an I/O Buffer available, it MUST invoke the Get_Data Operational Primitive qualified with the R2T PDU. See Section 7.3.6 for details on the handling of the R2T PDU.

对于请求的数据,当目标的iSCSI层具有可用的I/O缓冲区时,它必须调用使用R2T PDU限定的Get_数据操作原语。有关R2T PDU处理的详细信息,请参见第7.3.6节。

When the data transfer associated with this SCSI Write operation is complete, the iSCSI layer at the target MUST invoke the Send_Control Operational Primitive when it is ready to send the SCSI Response PDU. Upon receiving a SendSE or SendInvSE Message containing the SCSI Response PDU, the iSER layer at the initiator MUST notify the iSCSI layer at the initiator by invoking the Control_Notify Operational Primitive qualified with the SCSI Response PDU. See Section 7.3.2 for details on the handling of the SCSI Response PDU.

当与此SCSI写入操作相关联的数据传输完成时,目标的iSCSI层必须在准备发送SCSI响应PDU时调用Send_Control操作原语。在接收到包含SCSI响应PDU的SendSE或SendInvSE消息后,启动器的iSER层必须通过调用SCSI响应PDU限定的Control_notify Operational原语来通知启动器的iSCSI层。有关SCSI响应PDU处理的详细信息,请参阅第7.3.2节。

9.5.2. SCSI Read Operation
9.5.2. SCSI读取操作

The iSCSI layer at the initiator MUST invoke the Send_Control Operational Primitive to request that the iSER layer at the initiator to send the SCSI read command. The iSER layer at the initiator MUST request that the RCaP layer transmit a SendSE Message with the message payload consisting of the iSER header followed by the SCSI Command PDU. The iSER layer at the initiator MUST Advertise the Read STag in the iSER header of the SendSE Message, as described in Section 9.2. Upon receiving the SendSE Message, the iSER layer at the target MUST notify the iSCSI layer at the target by invoking the Control_Notify Operational Primitive qualified with the SCSI Command PDU. See Section 7.3.1 for details on the handling of the SCSI read command.

启动器上的iSCSI层必须调用Send_Control操作原语,以请求启动器上的iSER层发送SCSI读取命令。启动器处的iSER层必须请求RCaP层传输SendSE消息,消息有效负载由iSER头和SCSI命令PDU组成。如第9.2节所述,启动器的iSER层必须在SendSE消息的iSER头中公布读取STag。接收到SendSE消息后,目标服务器的iSER层必须通过调用SCSI命令PDU限定的Control_notify Operational原语来通知目标服务器的iSCSI层。有关SCSI读取命令处理的详细信息,请参阅第7.3.1节。

When the requested SCSI data is available in the I/O Buffer, the iSCSI layer at the target MUST invoke the Put_Data Operational Primitive qualified with the SCSI Data-in PDU. See Section 7.3.5 for details on the handling of the SCSI Data-in PDU.

当请求的SCSI数据在I/O缓冲区中可用时,目标的iSCSI层必须调用在PDU中使用SCSI数据限定的Put_数据操作原语。有关PDU中SCSI数据处理的详细信息,请参见第7.3.5节。

When the data transfer associated with this SCSI Read operation is complete, the iSCSI layer at the target MUST invoke the Send_Control Operational Primitive when it is ready to send the SCSI Response PDU. Upon receiving the SendInvSE Message containing the SCSI Response PDU, the iSER layer at the initiator MUST notify the iSCSI layer at the initiator by invoking the Control_Notify Operational Primitive qualified with the SCSI Response PDU. See Section 7.3.2 for details on the handling of the SCSI Response PDU.

当与此SCSI读取操作相关联的数据传输完成时,目标的iSCSI层必须在准备发送SCSI响应PDU时调用Send_Control操作原语。在接收到包含SCSI响应PDU的SendInvSE消息后,启动器的iSER层必须通过调用SCSI响应PDU限定的Control_notify Operational原语来通知启动器的iSCSI层。有关SCSI响应PDU处理的详细信息,请参阅第7.3.2节。

9.5.3. Bidirectional Operation
9.5.3. 双向操作

The initiator and the target handle the SCSI Write and the SCSI Read portions of this bidirectional operation the same as described in Sections 9.5.1 and 9.5.2, respectively.

启动器和目标分别按照第9.5.1节和第9.5.2节中的描述处理此双向操作的SCSI写入和SCSI读取部分。

10. iSER Error Handling and Recovery
10. iSER错误处理和恢复

RCaP provides the iSER layer with reliable in-order delivery. Therefore, the error management needs of an iSER-assisted connection are somewhat different than those of a Traditional iSCSI connection.

RCaP为iSER层提供可靠的订单交付。因此,iSER辅助连接的错误管理需求与传统iSCSI连接有所不同。

10.1. Error Handling
10.1. 错误处理

iSER error handling is described in the following sections, classified loosely based on the sources of errors:

iSER错误处理在以下章节中进行了描述,并根据错误来源进行了松散分类:

1. Those originating at the transport layer (e.g., TCP).

1. 源于传输层(如TCP)的协议。

2. Those originating at the RCaP layer.

2. 源于RCaP层的。

3. Those originating at the iSER layer.

3. 那些源于iSER层的。

4. Those originating at the iSCSI layer.

4. 源于iSCSI层的。

10.1.1. Errors in the Transport Layer
10.1.1. 传输层中的错误

If the transport layer is TCP, then TCP packets with detected errors are silently dropped by the TCP layer and result in retransmission at the TCP layer. This has no impact on the iSER layer. However, connection loss (e.g., link failure) and unexpected termination (e.g., TCP graceful or abnormal close without the iSCSI Logout exchanges) at the transport layer will cause the iSCSI/iSER connection to be terminated as well.

如果传输层是TCP,则TCP层会自动丢弃检测到错误的TCP数据包,并导致TCP层的重新传输。这对iSER层没有影响。但是,传输层的连接丢失(例如,链路故障)和意外终止(例如,TCP正常关闭或在没有iSCSI注销交换的情况下异常关闭)也会导致iSCSI/iSER连接终止。

10.1.1.1. Failure in the Transport Layer before RCaP Mode Is Enabled
10.1.1.1. 启用RCaP模式前传输层出现故障

If the connection is lost or terminated before the iSCSI layer invokes the Allocate_Connection_Resources Operational Primitive, the login process is terminated and no further action is required.

如果连接在iSCSI层调用Allocate_connection_Resources操作原语之前丢失或终止,则登录过程将终止,无需进一步操作。

If the connection is lost or terminated after the iSCSI layer has invoked the Allocate_Connection_Resources Operational Primitive, then the iSCSI layer MUST request that the iSER layer deallocate all connection resources by invoking the Deallocate_Connection_Resources Operational Primitive.

如果在iSCSI层调用Allocate_connection_Resources操作原语后连接丢失或终止,则iSCSI层必须通过调用deallocate_connection_Resources操作原语请求iSER层取消分配所有连接资源。

10.1.1.2. Failure in the Transport Layer after RCaP Mode Is Enabled
10.1.1.2. 启用RCaP模式后传输层出现故障

If the connection is lost or terminated after the iSCSI layer has invoked the Enable_Datamover Operational Primitive, the iSER layer MUST notify the iSCSI layer of the connection loss by invoking the Connection_Terminate_Notify Operational Primitive. Prior to invoking the Connection_Terminate_Notify Operational Primitive, the iSER layer MUST perform the actions described in Section 5.2.3.2.

如果在iSCSI层调用Enable_Datamover操作原语后连接丢失或终止,iSER层必须通过调用connection_Terminate_notify操作原语通知iSCSI层连接丢失。在调用连接终止通知操作原语之前,iSER层必须执行第5.2.3.2节中描述的操作。

10.1.2. Errors in the RCaP Layer
10.1.2. RCaP层中的错误

The RCaP layer does not have error recovery operations built in. If errors are detected at the RCaP layer, the RCaP layer will terminate the RCaP Stream and the associated connection.

RCaP层没有内置错误恢复操作。如果在RCaP层检测到错误,RCaP层将终止RCaP流和相关连接。

10.1.2.1. Errors Detected in the Local RCaP Layer
10.1.2.1. 在本地RCaP层中检测到错误

If an error is encountered at the local RCaP layer, the RCaP layer MAY send a Terminate Message to the Remote Peer to report the error if possible. (For iWARP, see [RDMAP] for the list of errors where a Terminate Message is sent.) The RCaP layer is responsible for terminating the connection. After the RCaP layer notifies the iSER layer that the connection is terminated, the iSER layer MUST notify the iSCSI layer by invoking the Connection_Terminate_Notify Operational Primitive. Prior to invoking the Connection_Terminate_Notify Operational Primitive, the iSER layer MUST perform the actions described in Section 5.2.3.2.

如果在本地RCaP层遇到错误,RCaP层可能会向远程对等方发送终止消息以报告错误(如果可能)。(对于iWARP,请参阅[RDMAP]了解发送终止消息时的错误列表。)RCaP层负责终止连接。RCaP层通知iSER层连接已终止后,iSER层必须通过调用connection_Terminate_notify操作原语通知iSCSI层。在调用连接终止通知操作原语之前,iSER层必须执行第5.2.3.2节中描述的操作。

10.1.2.2. Errors Detected in the RCaP Layer at the Remote Peer
10.1.2.2. 在远程对等机的RCaP层中检测到错误

If an error is encountered at the RCaP layer at the Remote Peer, the RCaP layer at the Remote Peer may send a Terminate Message to report the error if possible. If it is unable to send the Terminate Message, the connection is terminated. This is treated the same as a failure in the transport layer after RDMA is enabled as described in Section 10.1.1.2.

如果远程对等方的RCaP层遇到错误,远程对等方的RCaP层可能会发送终止消息以报告错误(如果可能)。如果无法发送终止消息,则连接将终止。如第10.1.1.2节所述,启用RDMA后,这被视为传输层中的故障。

If an error is encountered at the RCaP layer at the Remote Peer and it is able to send a Terminate Message, the RCaP layer at the Remote Peer is responsible for terminating the connection. After the local RCaP layer notifies the iSER layer that the connection is terminated, the iSER layer MUST notify the iSCSI layer by invoking the Connection_Terminate_Notify Operational Primitive. Prior to invoking the Connection_Terminate_Notify Operational Primitive, the iSER layer MUST perform the actions described in Section 5.2.3.2.

如果远程对等方的RCaP层遇到错误,并且能够发送终止消息,则远程对等方的RCaP层负责终止连接。在本地RCaP层通知iSER层连接已终止后,iSER层必须通过调用connection_Terminate_notify操作原语通知iSCSI层。在调用连接终止通知操作原语之前,iSER层必须执行第5.2.3.2节中描述的操作。

10.1.3. Errors in the iSER Layer
10.1.3. iSER层中的错误

The error handling due to errors at the iSER layer is described in the following sections.

iSER层错误导致的错误处理将在以下部分中描述。

10.1.3.1. Insufficient Connection Resources to Support RCaP at Connection Setup

10.1.3.1. 连接资源不足,无法在连接设置时支持RCaP

After the iSCSI layer at the initiator invokes the Allocate_Connection_Resources Operational Primitive during the iSCSI Login Negotiation Phase, if the iSER layer at the initiator fails to allocate the connection resources necessary to support RCaP, it MUST return a status of failure to the iSCSI layer at the initiator. The iSCSI layer at the initiator MUST terminate the connection as described in Section 5.2.3.1.

在iSCSI登录协商阶段,发起方的iSCSI层调用Allocate_Connection_Resources操作原语后,如果发起方的iSER层未能分配支持RCaP所需的连接资源,则它必须向发起方的iSCSI层返回失败状态。启动器处的iSCSI层必须按照第5.2.3.1节所述终止连接。

After the iSCSI layer at the target invokes the Allocate_Connection_Resources Operational Primitive during the iSCSI Login Negotiation Phase, if the iSER layer at the target fails to allocate the connection resources necessary to support RCaP, it MUST return a status of failure to the iSCSI layer at the target. The iSCSI layer at the target MUST send a Login Response with a status class of 3 (Target Error), and a status code of "0302" (Out of Resources). The iSCSI layers at the initiator and the target MUST terminate the connection as described in Section 5.2.3.1.

在iSCSI登录协商阶段,目标的iSCSI层调用Allocate_Connection_Resources操作原语后,如果目标的iSER层未能分配支持RCaP所需的连接资源,则必须向目标的iSCSI层返回失败状态。目标位置的iSCSI层必须发送状态类为3(目标错误)和状态代码为“0302”(资源不足)的登录响应。启动器和目标的iSCSI层必须按照第5.2.3.1节所述终止连接。

10.1.3.2. iSER Negotiation Failures
10.1.3.2. iSER协商失败

If the RCaP or iSER related parameters declared by the initiator in the iSER Hello Message are unacceptable to the iSER layer at the target, the iSER layer at the target MUST set the Reject (REJ) flag, as described in Section 9.4, in the iSER HelloReply Message. The following are the cases when the iSER layer MUST set the REJ flag to one in the HelloReply Message:

如果发起方在iSER Hello消息中声明的RCaP或iSER相关参数对目标iSER层不可接受,则目标iSER层必须在iSER HelloReply消息中设置拒绝(REJ)标志,如第9.4节所述。以下是iSER层必须在HelloReply消息中将REJ标志设置为1的情况:

* The initiator-declared iSER-IRD value is greater than 0 and the target-declared iSER-ORD value is 0.

* 启动器声明的iSER IRD值大于0,目标声明的iSER ORD值为0。

* The initiator-supported and the target-supported iSER protocol versions do not overlap.

* 受支持的启动器和受支持的目标iSER协议版本不重叠。

After requesting that the RCaP layer send the iSER HelloReply Message, the handling of the error situation is the same as that for iSER format errors as described in Section 10.1.3.3.

在请求RCaP层发送iSER HelloReply消息后,错误情况的处理与第10.1.3.3节中描述的iSER格式错误的处理相同。

10.1.3.3. iSER Format Errors
10.1.3.3. iSER格式错误

The following types of errors in an iSER header are considered format errors:

iSER标头中的以下类型错误被视为格式错误:

* Illegal contents of any iSER header field

* 任何iSER头字段的非法内容

* Inconsistent field contents in an iSER header

* iSER标头中的字段内容不一致

* Length error for an iSER Hello or HelloReply Message (see Section 9.3 and 9.4)

* iSER Hello或HelloReply消息的长度错误(参见第9.3和9.4节)

When a format error is detected, the following events MUST occur in the specified sequence:

检测到格式错误时,必须按指定顺序发生以下事件:

1. The iSER layer MUST request that the RCaP layer terminate the RCaP Stream. The RCaP layer MUST terminate the associated connection.

1. iSER层必须请求RCaP层终止RCaP流。RCaP层必须终止相关连接。

2. The iSER layer MUST notify the iSCSI layer of the connection termination by invoking the Connection_Terminate_Notify Operational Primitive. Prior to invoking the Connection_Terminate_Notify Operational Primitive, the iSER layer MUST perform the actions described in Section 5.2.3.2.

2. iSER层必须通过调用connection_Terminate_notify操作原语通知iSCSI层连接终止。在调用连接终止通知操作原语之前,iSER层必须执行第5.2.3.2节中描述的操作。

10.1.3.4. iSER Protocol Errors
10.1.3.4. iSER协议错误

The first iSER Message sent by the iSER layer at the initiator after transitioning into iSER-assisted mode MUST be the iSER Hello Message (see Section 9.3). Likewise, the first iSER Message sent by the iSER layer at the target after transitioning into iSER-assisted mode MUST be the iSER HelloReply Message (see Section 9.4). Failure to send the iSER Hello or HelloReply Message, as indicated by the wrong Opcode in the iSER header, is a protocol error. The handling of this error situation is the same as that for iSER format errors as described in Section 10.1.3.3.

在转换到iSER辅助模式后,iSER层在启动器处发送的第一条iSER消息必须是iSER Hello消息(参见第9.3节)。同样,在转换到iSER辅助模式后,iSER层在目标上发送的第一条iSER消息必须是iSER HelloReply消息(参见第9.4节)。未能发送iSER Hello或HelloReply消息(如iSER头中的错误操作码所示)是一个协议错误。该错误情况的处理与第10.1.3.3节所述iSER格式错误的处理相同。

If the sending side of an iSER-enabled connection acts in a manner not permitted by the negotiated or declared login/text operational key values as described in Section 6, this is a protocol error, and the receiving side MAY handle this the same as for iSER format errors as described in Section 10.1.3.3.

如果启用iSER的连接的发送端以第6节中所述协商或声明的登录/文本操作键值不允许的方式进行操作,则这是一个协议错误,接收方可以按照第10.1.3.3节中所述的iSER格式错误处理此错误。

10.1.4. Errors in the iSCSI Layer
10.1.4. iSCSI层中的错误

The error handling due to errors at the iSCSI layer is described in the following sections. For error recovery, see Section 10.2.

以下各节介绍了iSCSI层错误导致的错误处理。有关错误恢复,请参见第10.2节。

10.1.4.1. iSCSI Format Errors
10.1.4.1. iSCSI格式错误

When an iSCSI format error is detected, the iSCSI layer MUST request that the iSER layer terminate the RCaP Stream by invoking the Connection_Terminate Operational Primitive. For more details on the connection termination, see Section 5.2.3.1.

当检测到iSCSI格式错误时,iSCSI层必须通过调用Connection_terminate操作原语请求iSER层终止RCaP流。有关连接终端的更多详细信息,请参见第5.2.3.1节。

10.1.4.2. iSCSI Digest Errors
10.1.4.2. iSCSI摘要错误

In the iSER-assisted mode, the iSCSI layer will not see any digest error because both the HeaderDigest and the DataDigest keys are negotiated to "None".

在iSER辅助模式下,iSCSI层将不会看到任何摘要错误,因为HeaderDigest和DataDigest密钥都协商为“无”。

10.1.4.3. iSCSI Sequence Errors
10.1.4.3. iSCSI序列错误

For Traditional iSCSI, sequence errors are caused by dropped PDUs due to header or data digest errors. Since digests are not used in iSER-assisted mode and the RCaP layer will deliver all messages in the order they were sent, sequence errors will not occur in iSER-assisted mode.

对于传统iSCSI,序列错误是由于标头或数据摘要错误导致PDU丢失而导致的。由于摘要不在iSER辅助模式下使用,并且RCaP层将按照发送顺序发送所有消息,因此在iSER辅助模式下不会发生序列错误。

10.1.4.4. iSCSI Protocol Error
10.1.4.4. iSCSI协议错误

When the iSCSI layer handles certain protocol errors by dropping the connection, the error handling is the same as that for iSCSI format errors as described in Section 10.1.4.1.

当iSCSI层通过断开连接来处理某些协议错误时,错误处理与第10.1.4.1节中描述的iSCSI格式错误相同。

When the iSCSI layer uses the iSCSI Reject PDU and response codes to handle certain other protocol errors, no special handling at the iSER layer is required.

当iSCSI层使用iSCSI拒绝PDU和响应代码来处理某些其他协议错误时,不需要在iSER层进行特殊处理。

10.1.4.5. SCSI Timeouts and Session Errors
10.1.4.5. SCSI超时和会话错误

SCSI Timeouts and Session Errors are handled at the iSCSI layer and no special handling at the iSER layer is required.

SCSI超时和会话错误在iSCSI层处理,不需要在iSER层进行特殊处理。

10.1.4.6. iSCSI Negotiation Failures
10.1.4.6. iSCSI协商失败

For negotiation failures that happen during the Login Phase at the initiator after the iSCSI layer has invoked the Allocate_Connection_Resources Operational Primitive and before the Enable_Datamover Operational Primitive has been invoked, the iSCSI layer MUST request that the iSER layer deallocate all connection resources by invoking the Deallocate_Connection_Resources Operational Primitive. The iSCSI layer at the initiator MUST terminate the connection.

对于在iSCSI层调用Allocate_Connection_Resources操作原语之后以及在调用Enable_Datamover操作原语之前在启动器的登录阶段发生的协商失败,iSCSI层必须通过调用deallocate_connection_resources操作原语请求iSER层释放所有连接资源。启动器上的iSCSI层必须终止连接。

For negotiation failures during the Login Phase at the target, the iSCSI layer can use a Login Response with a status class other than 0 (success) to terminate the Login Phase. If the iSCSI layer has invoked the Allocate_Connection_Resources Operational Primitive before the Enable_Datamover Operational Primitive has been invoked, the iSCSI layer at the target MUST request that the iSER layer at the target deallocate all connection resources by invoking the Deallocate_Connection_Resources Operational Primitive. The iSCSI layer at both the initiator and the target MUST terminate the connection.

对于目标登录阶段的协商失败,iSCSI层可以使用状态类不是0(成功)的登录响应来终止登录阶段。如果iSCSI层在调用Enable_Datamover操作原语之前调用了Allocate_Connection_Resources操作原语,则目标的iSCSI层必须通过调用deallocate_Connection_Resources操作原语请求目标的iSER层释放所有连接资源。启动器和目标上的iSCSI层都必须终止连接。

During the iSCSI Login Phase, if the iSCSI layer at the initiator receives a Login Response from the target with a status class other than 0 (Success) after the iSCSI layer at the initiator has invoked the Allocate_Connection_Resources Operational Primitive, the iSCSI layer MUST request the iSER layer to deallocate all connection resources by invoking the Deallocate_Connection_Resources Operational Primitive. The iSCSI layer MUST terminate the connection in this case.

在iSCSI登录阶段,如果在启动器的iSCSI层调用Allocate_Connection_Resources操作原语后,启动器的iSCSI层从目标接收到状态类不是0(成功)的登录响应,iSCSI层必须通过调用deallocate_connection_resources操作原语请求iSER层释放所有连接资源。在这种情况下,iSCSI层必须终止连接。

For negotiation failures during the Full Feature Phase, the error handling is left to the iSCSI layer and no special handling at the iSER layer is required.

对于完整功能阶段中的协商失败,错误处理留给iSCSI层,不需要在iSER层进行特殊处理。

10.2. Error Recovery
10.2. 错误恢复

Error recovery requirements of iSCSI/iSER are the same as that of Traditional iSCSI. All three ErrorRecoveryLevels as defined in [RFC3720] are supported in iSCSI/iSER.

iSCSI/iSER的错误恢复要求与传统iSCSI相同。iSCSI/iSER支持[RFC3720]中定义的所有三个ErrorRecoveryLevel。

* For ErrorRecoveryLevel 0, session recovery is handled by iSCSI and no special handling by the iSER layer is required.

* 对于ErrorRecoveryLevel 0,会话恢复由iSCSI处理,不需要iSER层进行特殊处理。

* For ErrorRecoveryLevel 1, see Section 10.2.1 on PDU Recovery.

* 有关ErrorRecoveryLevel 1,请参见第10.2.1节PDU恢复。

* For ErrorRecoveryLevel 2, see Section 10.2.2 on Connection Recovery.

* 有关ErrorRecoveryLevel 2,请参阅第10.2.2节“连接恢复”。

The iSCSI layer may invoke the Notice_Key_Values Operational Primitive during connection setup to request that the iSER layer take note of the value of the operational ErrorRecoveryLevel, as described in Sections 5.1.1 and 5.1.2.

iSCSI层可在连接设置期间调用Notice_Key_Values Operational原语,请求iSER层注意Operational ErrorRecoveryLevel的值,如第5.1.1和5.1.2节所述。

10.2.1. PDU Recovery
10.2.1. PDU恢复

As described in Sections 10.1.4.2 and 10.1.4.3, digest and sequence errors will not occur in the iSER-assisted mode. If the RCaP layer detects an error, it will close the iSCSI/iSER connection, as

如第10.1.4.2节和第10.1.4.3节所述,iSER辅助模式下不会出现摘要和序列错误。如果RCaP层检测到错误,它将关闭iSCSI/iSER连接,如下所示

described in Section 10.1.2. Therefore, PDU recovery is not useful in the iSER-assisted mode.

如第10.1.2节所述。因此,PDU恢复在iSER辅助模式下没有用处。

The iSCSI layer at the initiator SHOULD disable iSCSI timeout-driven PDU retransmissions.

启动器处的iSCSI层应禁用iSCSI超时驱动的PDU重新传输。

10.2.2. Connection Recovery
10.2.2. 连接恢复

The iSCSI layer at the initiator MAY reassign connection allegiance for non-immediate commands that are still in progress and are associated with the failed connection by using a Task Management Function Request with the TASK REASSIGN function. See Section 7.3.3 for more details.

启动器处的iSCSI层可以通过使用任务管理功能请求和任务重新分配功能,为仍在进行且与失败连接相关联的非即时命令重新分配连接忠诚。详见第7.3.3节。

When the iSCSI layer at the initiator does a task reassignment for a SCSI write command, it MUST qualify the Send_Control Operational Primitive invocation with DataDescriptorOut, which defines the I/O Buffer for both the non-immediate unsolicited data and the solicited data. This allows the iSCSI layer at the target to use recovery R2Ts to request data originally sent as unsolicited and solicited from the initiator.

当启动器的iSCSI层为SCSI写入命令执行任务重新分配时,它必须使用DataDescriptorRout来限定Send_Control操作原语调用,DataDescriptorRout定义了非即时非请求数据和请求数据的I/O缓冲区。这允许目标位置的iSCSI层使用恢复R2T来请求最初作为未经请求发送并从启动器请求的数据。

When the iSCSI layer at the target accepts a reassignment request for a SCSI read command, it MUST request that the iSER layer process SCSI Data-in for all unacknowledged data by invoking the Put_Data Operational Primitive. See Section 7.3.5 on the handling of SCSI Data-in.

当目标的iSCSI层接受SCSI读取命令的重新分配请求时,它必须请求iSER层通过调用Put_数据操作原语来处理所有未确认数据的SCSI数据。请参阅第7.3.5节中有关SCSI数据处理的内容。

When the iSCSI layer at the target accepts a reassignment request for a SCSI write command, it MUST request that the iSER layer process a recovery R2T for any non-immediate unsolicited data and any solicited data sequences that have not been received by invoking the Get_Data Operational Primitive. See Section 7.3.6 on the handling of Ready To Transfer (R2T).

当目标位置的iSCSI层接受SCSI写入命令的重新分配请求时,它必须请求iSER层通过调用Get_data Operational原语来处理任何非即时未请求数据和任何未接收到的请求数据序列的恢复R2T。见第7.3.6节,关于准备转移(R2T)的处理。

The iSCSI layer at the target MUST NOT issue recovery R2Ts on an iSCSI/iSER connection for a task for which the connection allegiance was never reassigned. The iSER layer at the target MAY reject such a recovery R2T received via the Get_Data Operational Primitive invocation from the iSCSI layer at the target, with an appropriate error code.

对于从未重新分配连接忠诚度的任务,目标位置的iSCSI层不得在iSCSI/iSER连接上发出恢复R2T。目标的iSER层可能会拒绝通过Get_Data Operational原语调用从目标的iSCSI层接收的恢复R2T,并返回相应的错误代码。

The iSER layer at the target will process the requests invoked by the Put_Data and Get_Data Operational Primitives for a reassigned task in the same way as for the original commands.

目标的iSER层将以与原始命令相同的方式处理由Put_数据和Get_数据调用的请求,用于重新分配的任务。

11. Security Considerations
11. 安全考虑

When iSER is layered on top of an RCaP layer and provides the RDMA extensions to the iSCSI protocol, the security considerations of iSER are the same as that of the underlying RCaP layer. For iWARP, this is described in [RDMAP] and [RDDPSEC].

当iSER分层在RCaP层之上并为iSCSI协议提供RDMA扩展时,iSER的安全注意事项与底层RCaP层的安全注意事项相同。对于iWARP,这在[RDMAP]和[RDDPSEC]中进行了描述。

Since the iSER-assisted iSCSI protocol is still functionally iSCSI from a security considerations perspective, all of the iSCSI security requirements as described in [RFC3720] and [RFC3723] apply. If the IPsec [IPSEC] mechanism is used, then it MUST be established before the connection transitions to the iSER-assisted mode. If iSER is layered on top of a non-IP based RCaP layer, all the security protocol mechanisms applicable to that RCaP layer are also applicable to an iSCSI/iSER connection. If iSER is layered on top of a non-IP protocol, the IPsec mechanism as specified in [RFC3720] MUST be implemented at any point where the iSER protocol enters the IP network (e.g., via gateways), and the non-IP protocol SHOULD implement (optional to use) a packet-by packet security protocol equal in strength to the IPsec mechanism specified by [RFC3720].

由于iSER辅助的iSCSI协议从安全考虑的角度来看在功能上仍然是iSCSI,因此[RFC3720]和[RFC3723]中描述的所有iSCSI安全要求都适用。如果使用IPsec[IPsec]机制,则必须在连接转换到iSER辅助模式之前建立该机制。如果iSER分层在非基于IP的RCaP层之上,则适用于该RCaP层的所有安全协议机制也适用于iSCSI/iSER连接。如果iSER是在非IP协议之上分层的,则[RFC3720]中规定的IPsec机制必须在iSER协议进入IP网络(例如,通过网关)的任何点实施,并且非IP协议应实施(可选使用)一个分组一个分组的安全协议,其强度等于[RFC3720]。

To minimize the potential for a denial-of-service attack, the iSCSI layer MUST NOT request that the iSER layer allocate the connection resources necessary to support RCaP until the iSCSI layer is sufficiently far along in the iSCSI Login Phase that it is reasonably certain that the peer side is not an attacker, as described in Sections 5.1.1 and 5.1.2.

为了将拒绝服务攻击的可能性降至最低,iSCSI层不得请求iSER层分配支持RCaP所需的连接资源,直到iSCSI层在iSCSI登录阶段足够远,可以合理确定对等方不是攻击者,如第5.1.1节和第5.1.2节所述。

Note that the IPsec requirements for this document are based on the version of IPsec specified in RFC 2401 [IPSEC] and related RFCs, as profiled by RFC 3723 [RFC3723], despite the existence of a newer version of IPsec specified in RFC 4301 [RFC4301] and related RFCs.

注意,本文件的IPsec要求基于RFC 2401[IPsec]和相关RFC中规定的IPsec版本,如RFC 3723[RFC3723]所述,尽管存在RFC 4301[RFC4301]和相关RFC中规定的较新版本的IPsec。

12. References
12. 工具书类
12.1. Normative References
12.1. 规范性引用文件

[RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka, M., and E. Zeidner, "Internet Small Computer Systems Interface (iSCSI)", RFC 3720, April 2004.

[RFC3720]Satran,J.,Meth,K.,Sapuntzakis,C.,Chadalapaka,M.,和E.Zeidner,“互联网小型计算机系统接口(iSCSI)”,RFC 3720,2004年4月。

[RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and F. Travostino, "Securing Block Storage Protocols over IP", RFC 3723, April 2004.

[RFC3723]Aboba,B.,Tseng,J.,Walker,J.,Rangan,V.,和F.Travostino,“通过IP保护块存储协议”,RFC 37232004年4月。

[RDMAP] Recio, R., Culley, P., Garcia, D., Hilland, J., and B. Metzler, "A Remote Direct Memory Access Protocol Specification", RFC 5040, October 2007.

[RDMAP]Recio,R.,Culley,P.,Garcia,D.,Hilland,J.,和B.Metzler,“远程直接内存访问协议规范”,RFC 50402007年10月。

[DDP] Shah, H., Pinkerton, J., Recio, R., and P. Culley, "Direct Data Placement over Reliable Transports", RFC 5041, October 2007.

[DDP]Shah,H.,Pinkerton,J.,Recio,R.,和P.Culley,“可靠传输上的直接数据放置”,RFC 50412007年10月。

[IPSEC] Kent, S. and R. Atkinson, "Security Architecture for the Internet Protocol", RFC 2401, November 1998.

[IPSEC]Kent,S.和R.Atkinson,“互联网协议的安全架构”,RFC 2401,1998年11月。

[MPA] Culley, P., Elzur, U., Recio, R., Bailey, S., and J. Carrier, "Marker PDU Aligned Framing for TCP Specification", RFC 5044, October 2007.

[MPA]Culley,P.,Elzur,U.,Recio,R.,Bailey,S.,和J.Carrier,“TCP规范的标记PDU对齐框架”,RFC 5044,2007年10月。

[RDDPSEC] Pinkerton, J. and E. Deleganes, "Direct Data Placement Protocol (DDP) / Remote Direct Memory Access Protocol (RDMAP) Security", RFC 5042, October 2007.

[RDDPSEC]Pinkerton,J.和E.Deleganes,“直接数据放置协议(DDP)/远程直接内存访问协议(RDMAP)安全”,RFC 50422007年10月。

[TCP] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, September 1981.

[TCP]Postel,J.,“传输控制协议”,STD 7,RFC 793,1981年9月。

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2119]Bradner,S.,“RFC中用于表示需求水平的关键词”,BCP 14,RFC 2119,1997年3月。

12.2. Informative References
12.2. 资料性引用

[SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2)

[SAM2]T10/1157D,SCSI体系结构模型-2(SAM-2)

[DA] Chadalapaka, M., Hufferd, J., Satran, J., and H. Shah, "DA: Datamover Architecture for the Internet Small Computer System Interface (iSCSI)", RFC 5047, October 2007.

[DA]Chadalapaka,M.,Hufferd,J.,Satran,J.,和H.Shah,“DA:互联网小型计算机系统接口(iSCSI)的数据移动器体系结构”,RFC 5047,2007年10月。

[IB] InfiniBand Architecture Specification Volume 1 Release 1.2, October 2004

[IB]InfiniBand体系结构规范第1卷第1.2版,2004年10月

[IPoIB] Chu, J. and V. Kashyap, "Transmission of IP over InfiniBand (IPoIB)", RFC 4391, April 2006.

[IPoIB]Chu,J.和V.Kashyap,“InfiniBand上的IP传输(IPoIB)”,RFC 4391,2006年4月。

[RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005.

[RFC4301]Kent,S.和K.Seo,“互联网协议的安全架构”,RFC 43012005年12月。

Appendix A. iWARP Message Format for iSER
附录A.iSER的iWARP消息格式

This section is for information only and is NOT part of the standard. It simply depicts the iWARP Message format for the various iSER Messages when the transport layer is TCP.

本节仅供参考,不属于本标准的一部分。它简单地描述了当传输层为TCP时各种iSER消息的iWARP消息格式。

A.1. iWARP Message Format for iSER Hello Message
A.1. iSER Hello消息的iWARP消息格式

The following figure depicts an iSER Hello Message encapsulated in an iWARP SendSE Message.

下图描述了封装在iWARP SendSE消息中的iSER Hello消息。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0010b | Zeros | 0001b | 0001b |           iSER-IRD            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0010b | Zeros | 0001b | 0001b |           iSER-IRD            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 6. SendSE Message Containing an iSER Hello Message

图6。包含iSER Hello消息的SendSE消息

A.2. iWARP Message Format for iSER HelloReply Message
A.2. iSER HelloReply消息的iWARP消息格式

The following figure depicts an iSER HelloReply Message encapsulated in an iWARP SendSE Message. The Reject (REJ) flag is set to 0.

下图描述了封装在iWARP SendSE消息中的iSER HelloReply消息。拒绝(REJ)标志设置为0。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0011b |Zeros|0| 0001b | 0001b |           iSER-ORD            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0011b |Zeros|0| 0001b | 0001b |           iSER-ORD            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 7. SendSE Message Containing an iSER HelloReply Message

图7。包含iSER HelloReply消息的SendSE消息

A.3. iWARP Message Format for SCSI Read Command PDU
A.3. SCSI读取命令PDU的iWARP消息格式

The following figure depicts a SCSI Read Command PDU embedded in an iSER Message encapsulated in an iWARP SendSE Message. For this particular example, in the iSER header, the Write STag Valid flag is set to zero, the Read STag Valid flag is set to one, the Write STag field is set to all zeros, and the Read STag field contains a valid Read STag.

下图描述了嵌入在iWARP SendSE消息中封装的iSER消息中的SCSI读取命令PDU。对于这个特定的示例,在iSER头中,Write STag Valid标志设置为零,Read STag Valid标志设置为1,Write STag字段设置为全零,Read STag字段包含有效的Read STag。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0001b |0|1|                  All zeros                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         All Zeros                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Read STag                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Read Command PDU                   |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0001b |0|1|                  All zeros                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         All Zeros                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Read STag                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Read Command PDU                   |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 8. SendSE Message Containing a SCSI Read Command PDU

图8。包含SCSI读取命令PDU的SendSE消息

A.4. iWARP Message Format for SCSI Read Data
A.4. SCSI读取数据的iWARP消息格式

The following figure depicts an iWARP RDMA Write Message carrying SCSI Read data in the payload:

下图描述了负载中承载SCSI读取数据的iWARP RDMA写消息:

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |   DDP Control | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Data Sink STag                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Data Sink Tagged Offset                     |
      +                                                               +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      SCSI Read data                           |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |   DDP Control | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Data Sink STag                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Data Sink Tagged Offset                     |
      +                                                               +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      SCSI Read data                           |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 9. RDMA Write Message Containing SCSI Read Data

图9。包含SCSI读取数据的RDMA写入消息

A.5. iWARP Message Format for SCSI Write Command PDU
A.5. SCSI写入命令PDU的iWARP消息格式

The following figure depicts a SCSI Write Command PDU embedded in an iSER Message encapsulated in an iWARP SendSE Message. For this particular example, in the iSER header, the Write STag Valid flag is set to one, the Read STag Valid flag is set to zero, the Write STag field contains a valid Write STag, and the Read STag field is set to all zeros since it is not used.

下图描述了嵌入在iWARP SendSE消息中封装的iSER消息中的SCSI写入命令PDU。对于这个特定的示例,在iSER头中,Write STag Valid标志设置为1,Read STag Valid标志设置为0,Write STag字段包含有效的Write STag,Read STag字段由于未使用而设置为全零。

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0001b |1|0|                  All zeros                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Write STag                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         All Zeros                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Write Command PDU                  |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Reserved                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0001b |1|0|                  All zeros                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Write STag                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         All Zeros                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Write Command PDU                  |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 10. SendSE Message Containing a SCSI Write Command PDU

图10。包含SCSI写入命令PDU的SendSE消息

A.6. iWARP Message Format for RDMA Read Request
A.6. RDMA读取请求的iWARP消息格式

An iSCSI R2T is transformed into an iWARP RDMA Read Request Message. The following figure depicts an iWARP RDMA Read Request Message:

iSCSI R2T转换为iWARP RDMA读取请求消息。下图描述了iWARP RDMA读取请求消息:

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Reserved (Not Used)                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              DDP (RDMA Read Request) Queue Number             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        DDP (RDMA Read Request) Message Sequence Number        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             DDP (RDMA Read Request) Message Offset            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                     Data Sink STag (SinkSTag)                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +                  Data Sink Tagged Offset (SinkTO)             +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  RDMA Read Message Size (RDMARDSZ)            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                     Data Source STag (SrcSTag)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +                 Data Source Tagged Offset (SrcTO)             +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Reserved (Not Used)                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              DDP (RDMA Read Request) Queue Number             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        DDP (RDMA Read Request) Message Sequence Number        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             DDP (RDMA Read Request) Message Offset            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                     Data Sink STag (SinkSTag)                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +                  Data Sink Tagged Offset (SinkTO)             +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  RDMA Read Message Size (RDMARDSZ)            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                     Data Source STag (SrcSTag)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +                 Data Source Tagged Offset (SrcTO)             +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 11. RDMA Read Request Message

图11。RDMA读取请求消息

A.7. iWARP Message Format for Solicited SCSI Write Data
A.7. 请求的SCSI写入数据的iWARP消息格式

The following figure depicts an iWARP RDMA Read Response Message carrying the solicited SCSI Write data in the payload:

下图描述了负载中携带请求的SCSI写入数据的iWARP RDMA读取响应消息:

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Data Sink STag                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Data Sink Tagged Offset                     |
      +                                                               +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Write Data                         |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Data Sink STag                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Data Sink Tagged Offset                     |
      +                                                               +
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Write Data                         |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 12. RDMA Read Response Message Containing SCSI Write Data

图12。包含SCSI写入数据的RDMA读取响应消息

A.8. iWARP Message Format for SCSI Response PDU
A.8. SCSI响应PDU的iWARP消息格式

The following figure depicts a SCSI Response PDU embedded in an iSER Message encapsulated in an iWARP SendInvSE Message:

下图描述了嵌入在iWARP SendInvSE消息中封装的iSER消息中的SCSI响应PDU:

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Invalidate STag                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0001b |0|0|                  All Zeros                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Response PDU                       |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        
       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         MPA Header            |  DDP Control  | RDMA Control  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Invalidate STag                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Send) Queue Number                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 (Send) Message Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      (Send) Message Offset                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | 0001b |0|0|                  All Zeros                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           All Zeros                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       SCSI Response PDU                       |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           MPA CRC                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        

Figure 13. SendInvSE Message Containing SCSI Response PDU

图13。包含SCSI响应PDU的SendInvSE消息

Appendix B. Architectural Discussion of iSER over InfiniBand
附录B.InfiniBand上iSER的架构讨论

This section explains how an InfiniBand network (with Gateways) would be structured. It is informational only and is intended to provide insight on how iSER is used in an InfiniBand environment.

本节介绍InfiniBand网络(带网关)的结构。本文仅供参考,旨在深入了解iSeries在InfiniBand环境中的使用方式。

B.1. The Host Side of the iSCSI and iSER Connections in InfiniBand
B.1. InfiniBand中iSCSI和iSER连接的主机端

Figure 14 defines the topologies in which iSCSI and iSER will be able to operate on an InfiniBand Network.

图14定义了iSCSI和iSER能够在InfiniBand网络上运行的拓扑。

   +---------+ +---------+ +---------+ +---------+ +--- -----+
   |  Host   | |  Host   | |   Host  | |   Host  | |   Host  |
   |         | |         | |         | |         | |         |
   +---+-+---+ +---+-+---+ +---+-+---+ +---+-+---+ +---+-+---+
   |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA|
   +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+
     |----+------|-----+-----|-----+-----|-----+-----|-----+---> To IB
   IB|        IB |        IB |        IB |        IB |    SubNet2 SWTCH
   +-v-----------v-----------v-----------v-----------v---------+
   |                  InfiniBand Switch for Subnet1            |
   +---+-----+--------+-----+--------+-----+------------v------+
       | TCA |        | TCA |        | TCA |            |
       +-----+        +-----+        +-----+            | IB
      /  IB   \      /  IB   \      /       \     +--+--v--+--+
     |  iSER   |    |  iSER   |    |  IPoIB  |    |  | TCA |  |
     | Gateway |    | Gateway |    | Gateway |    |  +-----+  |
     |   to    |    |   to    |    |   to    |    | Storage   |
     |  iSCSI  |    |  iSER   |    |   IP    |    | Controller|
     |   TCP   |    |  iWARP  |    |Ethernet |    +-----+-----+
     +---v-----|    +---v-----|    +----v----+
         | EN           | EN            | EN
         +--------------+---------------+----> to IP based storage
           Ethernet links that carry iSCSI or iWARP
        
   +---------+ +---------+ +---------+ +---------+ +--- -----+
   |  Host   | |  Host   | |   Host  | |   Host  | |   Host  |
   |         | |         | |         | |         | |         |
   +---+-+---+ +---+-+---+ +---+-+---+ +---+-+---+ +---+-+---+
   |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA| |HCA|
   +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+ +-v-+
     |----+------|-----+-----|-----+-----|-----+-----|-----+---> To IB
   IB|        IB |        IB |        IB |        IB |    SubNet2 SWTCH
   +-v-----------v-----------v-----------v-----------v---------+
   |                  InfiniBand Switch for Subnet1            |
   +---+-----+--------+-----+--------+-----+------------v------+
       | TCA |        | TCA |        | TCA |            |
       +-----+        +-----+        +-----+            | IB
      /  IB   \      /  IB   \      /       \     +--+--v--+--+
     |  iSER   |    |  iSER   |    |  IPoIB  |    |  | TCA |  |
     | Gateway |    | Gateway |    | Gateway |    |  +-----+  |
     |   to    |    |   to    |    |   to    |    | Storage   |
     |  iSCSI  |    |  iSER   |    |   IP    |    | Controller|
     |   TCP   |    |  iWARP  |    |Ethernet |    +-----+-----+
     +---v-----|    +---v-----|    +----v----+
         | EN           | EN            | EN
         +--------------+---------------+----> to IP based storage
           Ethernet links that carry iSCSI or iWARP
        

Figure 14. iSCSI and iSER on IB

图14。IB上的iSCSI和iSER

In Figure 14, the Host systems are connected via the InfiniBand Host Channel Adapters (HCAs) to the InfiniBand links. With the use of IB switch(es), the InfiniBand links connect the HCA to InfiniBand Target Channel Adapters (TCAs) located in gateways or Storage Controllers. An iSER-capable IB-IP Gateway converts the iSER Messages encapsulated in IB protocols to either standard iSCSI, or iSER Messages for iWARP. An [IPoIB] Gateway converts the InfiniBand [IPoIB] protocol to IP protocol, and in the iSCSI case, permits iSCSI to be operated on an IB Network between the Hosts and the [IPoIB] Gateway.

在图14中,主机系统通过InfiniBand主机通道适配器(HCA)连接到InfiniBand链路。通过使用IB交换机(es),InfiniBand链路将HCA连接到位于网关或存储控制器中的InfiniBand目标通道适配器(TCA)。支持iSER的IB-IP网关将封装在IB协议中的iSER消息转换为标准iSCSI或iWARP的iSER消息。[IPoIB]网关将InfiniBand[IPoIB]协议转换为IP协议,在iSCSI情况下,允许在主机和[IPoIB]网关之间的IB网络上操作iSCSI。

B.2. The Storage Side of the iSCSI and iSER Mixed Network Environment
B.2. iSCSI和iSER混合网络环境的存储端

Figure 15 shows a storage controller that has three different portal groups: one supporting only iSCSI (TPG-4), one supporting iSER/iWARP or iSCSI (TPG-2), and one supporting iSER/IB (TPG-1).

图15显示了具有三个不同入口组的存储控制器:一个仅支持iSCSI(TPG-4),一个支持iSER/iWARP或iSCSI(TPG-2),以及一个支持iSER/IB(TPG-1)。

                  |                |                |
                  |                |                |
            +--+--v--+----------+--v--+----------+--v--+--+
            |  | IB  |          |iWARP|          | EN  |  |
            |  |     |          | TCP |          | NIC |  |
            |  |(TCA)|          | RNIC|          |     |  |
            |  +-----|          +-----+          +-----+  |
            |   TPG-1            TPG-2            TPG-4   |
            |  9.1.3.3          9.1.2.4          9.1.2.6  |
            |                                             |
            |                  Storage Controller         |
            |                                             |
            +---------------------------------------------+
        
                  |                |                |
                  |                |                |
            +--+--v--+----------+--v--+----------+--v--+--+
            |  | IB  |          |iWARP|          | EN  |  |
            |  |     |          | TCP |          | NIC |  |
            |  |(TCA)|          | RNIC|          |     |  |
            |  +-----|          +-----+          +-----+  |
            |   TPG-1            TPG-2            TPG-4   |
            |  9.1.3.3          9.1.2.4          9.1.2.6  |
            |                                             |
            |                  Storage Controller         |
            |                                             |
            +---------------------------------------------+
        

Figure 15. Storage Controller with TCP, iWARP, and IB Connections

图15。具有TCP、iWARP和IB连接的存储控制器

The normal iSCSI portal group advertising processes (via the Service Location Protocol (SLP), the Internet Storage Name Service (iSNS), or SendTargets) are available to a Storage Controller.

存储控制器可以使用正常的iSCSI门户组发布过程(通过服务位置协议(SLP)、Internet存储名称服务(iSNS)或SendTargets)。

B.3. Discovery Processes for an InfiniBand Host
B.3. InfiniBand主机的发现过程

An InfiniBand Host system can gather portal group IP addresses from SLP, iSNS, or the SendTargets discovery processes by using TCP/IP via [IPoIB]. After obtaining one or more remote portal IP addresses, the Initiator uses the standard IP mechanisms to resolve the IP address to a local outgoing interface and the destination hardware address (Ethernet MAC or IB GID of the target or a gateway leading to the target). If the resolved interface is an [IPoIB] network interface, then the target portal can be reached through an InfiniBand fabric. In this case, the Initiator can establish an iSCSI/TCP or iSCSI/iSER session with the Target over that InfiniBand interface, using the Hardware Address (InfiniBand GID) obtained through the standard Address Resolution (ARP) processes.

InfiniBand主机系统可以通过[IPoIB]使用TCP/IP从SLP、iSNS或SendTargets发现进程收集门户组IP地址。获得一个或多个远程门户IP地址后,启动器使用标准IP机制将IP地址解析为本地传出接口和目标硬件地址(目标的以太网MAC或IB GID或通向目标的网关)。如果解析的接口是[IPoIB]网络接口,则可以通过InfiniBand结构访问目标门户。在这种情况下,启动器可以使用通过标准地址解析(ARP)过程获得的硬件地址(InfiniBand GID),通过该InfiniBand接口与目标建立iSCSI/TCP或iSCSI/iSER会话。

If more than one IP address is obtained through the discovery process, the Initiator should select a Target IP address that is on the same IP subnet as the Initiator, if one exists. This will avoid a potential overhead of going through a gateway when a direct path exists.

如果通过发现过程获得多个IP地址,则启动器应选择与启动器位于同一IP子网上的目标IP地址(如果存在)。这将避免在存在直接路径时通过网关的潜在开销。

In addition, a user can configure manual static IP route entries if a particular path to the target is preferred.

此外,如果首选到目标的特定路径,用户可以配置手动静态IP路由条目。

B.4. IBTA Connection Specifications
B.4. IBTA连接规范

The InfiniBand Trade Association (IBTA) connection specifications are outside the scope of this document, but it is expected that the IBTA has or will define:

InfiniBand Trade Association(IBTA)连接规范不在本文档范围内,但预计IBTA已经或将定义:

* The iSER ServiceID.

* iSER服务ID。

* A Means for permitting a Host to establish a connection with a peer InfiniBand end-node, and to fall back to iSCSI/TCP over [IPoIB] if that peer indicates iSER is not supported.

* 一种允许主机与对等InfiniBand端节点建立连接的方法,如果该对等方指示不支持iSER,则允许主机通过[IPoIB]退回到iSCSI/TCP。

* A Means for permitting the Host to establish connections with IB iSER connections on storage controllers or IB iSER connected Gateways in preference to [IPoIB] connected Gateways/Bridges or connections to Target Storage Controllers that also accept iSCSI via [IPoIB].

* 一种允许主机与存储控制器上的IB iSER连接或IB iSER连接的网关建立连接的方法,优先于[IPoIB]连接的网关/网桥或与也通过[IPoIB]接受iSCSI的目标存储控制器的连接。

* A Means for combining the IB ServiceID for iSER and the IP port number such that the IB Host can use normal IB connection processes, yet ensure that the iSER target peer can actually connect to the required IP port number.

* 一种将iSER的IB ServiceID与IP端口号相结合的方法,以便IB主机可以使用正常的IB连接过程,同时确保iSER目标对等方可以实际连接到所需的IP端口号。

Acknowledgments

致谢

This protocol was developed by a design team that, in addition to the authors, included Dwight Barron (HP), John Carrier (formerly from Adaptec), Ted Compton (EMC), Paul R. Culley (HP), Yaron Haviv (Voltaire), Jeff Hilland (HP), Mike Krause (HP), Alex Nezhinsky (Voltaire), Jim Pinkerton (Microsoft), Renato J. Recio (IBM), Julian Satran (IBM), Tom Talpey (Network Appliance), and Jim Wendt (HP). Special thanks to David Black (EMC) for his extensive review comments.

该协议由一个设计团队开发,除作者外,该设计团队还包括德怀特·巴伦(HP)、约翰·卡利(以前来自Adaptec)、泰德·康普顿(EMC)、保罗·R·卡利(HP)、亚龙·哈维夫(伏尔泰)、杰夫·希尔兰(HP)、迈克·克劳斯(HP)、亚历克斯·内日恩斯基(伏尔泰)、吉姆·平克顿(Microsoft)、雷纳托·J·雷西奥(IBM)、朱利安·萨特兰(IBM),Tom Talpey(网络设备)和Jim Wendt(惠普)。特别感谢David Black(EMC)发表了广泛的评论。

Author's Address

作者地址

Mallikarjun Chadalapaka Hewlett-Packard Company 8000 Foothills Blvd. Roseville, CA 95747-5668, USA Phone: +1-916-785-5621 EMail: cbm@rose.hp.com

Mallikarjun Chadalapaka Hewlett-Packard Company 8000 Foothills Blvd。美国加利福尼亚州罗斯维尔95747-5668电话:+1-916-785-5621电子邮件:cbm@rose.hp.com

Uri Elzur Broadcom Corporation 5300 California Avenue Irvine, CA 92617, USA Phone: +1-949-926-6432 EMail: Uri@Broadcom.com

Uri Elzur Broadcom Corporation美国加利福尼亚州欧文市加利福尼亚大道5300号电话:+1-949-926-6432电子邮件:Uri@Broadcom.com

John Hufferd Brocade Communications Systems, Inc. 1745 Technology Drive San Jose, CA 95110, USA Phone: +1-408-333-5244 EMail: jhufferd@brocade.com

John Hufferd Brocade Communications Systems,Inc.美国加利福尼亚州圣何塞市科技大道1745号,邮编95110电话:+1-408-333-5244电子邮件:jhufferd@brocade.com

Mike Ko IBM Corp. 650 Harry Rd. San Jose, CA 95120, USA Phone: +1-408-927-2085 EMail: mako@us.ibm.com

Mike Ko IBM Corp.美国加利福尼亚州圣何塞哈里路650号电话:+1-408-927-2085电子邮件:mako@us.ibm.com

Hemal Shah Broadcom Corporation 5300 California Avenue Irvine, CA 92617, USA Phone: +1-949-926-6941 EMail: hemal@broadcom.com

Hemal Shah Broadcom Corporation美国加利福尼亚州欧文市加利福尼亚大道5300号电话:+1-949-926-6941电子邮件:hemal@broadcom.com

Patricia Thaler Broadcom Corporation 5300 California Avenue Irvine, CA 92617, USA Phone: +1-916-570-2707 EMail: pthaler@broadcom.com

Patricia Thaler Broadcom Corporation美国加利福尼亚州欧文市加利福尼亚大道5300号92617电话:+1-916-570-2707电子邮件:pthaler@broadcom.com

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