draft-ietf-storm-iscsi-sam-09.txt   rfc7144.txt 
Storage Maintenance (StorM) Working Group Frederick Knight
Internet Draft NetApp
Intended status: Standards Track M. Chadalapaka
Expires: February 2014 Microsoft
August 2013
Internet Small Computer Systems Interface (iSCSI) SCSI Features
Update
draft-ietf-storm-iscsi-sam-09.txt
Abstract
Internet Small Computer Systems Interface (iSCSI) is a SCSI
transport protocol that maps the SCSI family of protocols onto
TCP/IP. The iSCSI protocol as specified in RFCxxx (and as
previously specified by the combination of RFC 3720 and RFC
5048) is based on the SAM-2 (SCSI Architecture Model - 2)
version of the SCSI family of protocols. This document
defines enhancements to the iSCSI protocol to support certain
additional features of the SCSI protocol that were defined in
SAM-3, SAM-4, and SAM-5.
This document is a companion document to RFCxxx. Internet Engineering Task Force (IETF) F. Knight
Request for Comments: 7144 NetApp
Category: Standards Track M. Chadalapaka
ISSN: 2070-1721 Microsoft
April 2014
-------------------------------------------------------- Internet Small Computer System Interface (iSCSI)
RFC EDITORS NOTE: The above two references to RFCxxx should SCSI Features Update
reference the RFC number assigned to the draft-ietf-storm-
iscsi-cons-xx document, and this note should be removed.
--------------------------------------------------------
Status of this Memo Abstract
This Internet-Draft is submitted to IETF in full conformance with Internet Small Computer System Interface (iSCSI) is a SCSI
the provisions of BCP 78 and BCP 79. transport protocol that maps the SCSI family of protocols onto
TCP/IP. The iSCSI protocol as specified in RFC 7143 (and as
previously specified by the combination of RFC 3720 and RFC
5048) is based on the SAM-2 (SCSI Architecture Model - 2)
version of the SCSI family of protocols. This document
defines enhancements to the iSCSI protocol to support certain
additional features of the SCSI protocol that were defined in
SAM-3, SAM-4, and SAM-5.
Internet-Drafts are working documents of the Internet Engineering This document is a companion document to RFC 7143.
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six Status of This Memo
months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-
Drafts as reference material or to cite them other than as "work
in progress."
The list of current Internet-Drafts can be accessed at This is an Internet Standards Track document.
http://www.ietf.org/1id-abstracts.html.
The list of Internet-Draft Shadow Directories can be accessed at This document is a product of the Internet Engineering Task Force
http://www.ietf.org/shadow.html. (IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by
the Internet Engineering Steering Group (IESG). Further
information on Internet Standards is available in Section 2 of
RFC 5741.
This Internet-Draft will expire February, 2014. Information about the current status of this document, any
errata, and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7144.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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without warranty as described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction.................................................. 3 1. Introduction ....................................................4
2. Definitions, Acronyms, and Document Summary................... 3 2. Definitions, Acronyms, and Document Summary .....................4
2.1 Definitions ........................................... 3 2.1. Definitions ................................................4
2.2 Acronyms .............................................. 3 2.2. Acronyms ...................................................4
2.3 New Semantics ......................................... 3 2.3. New Semantics ..............................................4
3. Terminology Mapping........................................... 4 3. Terminology Mapping .............................................5
4. New Feature Use............................................... 7 4. New Feature Use .................................................7
4.1 Negotiation of New Feature Use............................... 7 4.1. Negotiation of New Feature Use .............................7
4.2 Impact on standard INQUIRY data.............................. 7 4.2. Impact on Standard INQUIRY Data - iSCSI Version
5. SCSI Commands................................................. 8 Descriptors ................................................8
5.1 SCSI Command Additions ................................ 8 5. SCSI Commands ...................................................9
5.1.1 Command Priority (byte 2) ......................... 9 5.1. SCSI Command Additions .....................................9
5.2 SCSI Response Additions .............................. 10 5.1.1. Command Priority (Byte 2) ..........................10
5.2.1 Status Qualifier ................................. 11 5.2. SCSI Response Additions ...................................11
5.2.2 Data Segment - Sense and Response Data Segment ... 11 5.2.1. Status Qualifier ...................................12
6. Task Management Functions.................................... 12 5.2.2. Data Segment - Sense and Response Data Segment .....12
6.1 Task Management Function Request PDU ................. 12 6. Task Management Functions ......................................13
6.2 Existing Task Management Functions ................... 12 6.1. Task Management Function Request PDU ......................13
6.3 Task Management Function Additions ................... 13 6.2. Existing Task Management Functions ........................14
6.3.1 LUN field ........................................ 14 6.3. Task Management Function Additions ........................14
6.3.2 Referenced Task Tag .............................. 14 6.3.1. LUN Field ..........................................15
6.3.3 RefCmdSN ......................................... 15 6.3.2. Referenced Task Tag ................................16
6.4 Task Management Function Responses ................... 16 6.3.3. RefCmdSN ...........................................16
6.4.1 Task Management Function Response PDU ............ 16 6.4. Task Management Function Responses ........................17
6.4.2 Task Management Function Response Additions ...... 17 6.4.1. Task Management Function Response PDU ..............17
6.5 Task Management Requests Affecting Multiple Tasks .... 18 6.4.2. Task Management Function Response Additions ........18
7. Login/Text Operational Text Keys............................. 18 6.5. Task Management Requests Affecting Multiple Tasks .........19
7.1 New Operational Text Keys ............................ 18 7. Login/Text Operational Text Keys ...............................19
7.1.1 iSCSIProtocolLevel ............................... 18 7.1. New Operational Text Keys .................................19
8. Security Considerations...................................... 19 7.1.1. iSCSIProtocolLevel .................................19
9. IANA Considerations.......................................... 19 8. Security Considerations ........................................20
10. References.................................................. 22 9. IANA Considerations ............................................21
11. Acknowledgements............................................ 23 10. References ....................................................24
1. Introduction 10.1. Normative References .....................................24
10.2. Informative References ...................................24
The original iSCSI protocol [RFC3720] was built based on the 11. Acknowledgements ..............................................24
[SAM2] model for SCSI. Several new features and capabilities
have been added to the SCSI Architecture Model in the intervening
years (at the time of publication of this document, SAM-5 was the
current version of the SCSI Architecture Model). This document
is not a complete revision of [RFC3720]. Instead, this document
is intended as a companion document to [draft-ietf-storm-iscsi-
cons-xx]; this document may also be used as a companion document
to the combination of [RFC3720] and [RFC5048], although both of
those RFCs have been obsolete by [draft-ietf-storm-iscsi-cons-
xx].
--------------------------------------------------------
RFC EDITORS NOTE: The above references to [draft-ietf-storm-
iscsi-cons-xx] should reference the RFC number assigned to
that document, and this note should be removed.
--------------------------------------------------------
2. Definitions, Acronyms, and Document Summary
2.1 Definitions
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].
2.2 Acronyms
ISID Initiator Session Identifier
LU Logical Unit
PDU Protocol Data Unit
SAM-5 SCSI Architecture Model - 5 (see [SAM5])
TMF Task Management Function
2.3 New Semantics 1. Introduction
This document specifies new iSCSI semantics. This section The original iSCSI protocol [RFC3720] was built based on the [SAM2]
summarizes the contents of the document. model for SCSI. Several new features and capabilities have been
added to the SCSI Architecture Model in the intervening years (at the
time of publication of this document, SAM-5 was the current version
of the SCSI Architecture Model). This document is not a complete
revision of [RFC3720]. Instead, this document is intended as a
companion document to RFC 7143; this document may also be used as a
companion document to the combination of [RFC3720] and [RFC5048],
although both of those RFCs have been obsoleted by [RFC7143].
Section 3: The mapping of iSCSI objects to SAM-5 objects For more information on the SCSI Architecture Model and SCSI Primary
The iSCSI node may contain both initiator and Commands - 4, contact the INCITS T10 Technical Committee for SCSI
target capabilities. Storage Interfaces at <http://www.t10.org>.
Section 4: The protocol used to negotiate the use of the new 2. Definitions, Acronyms, and Document Summary
capabilities described in this document.
Section 5: New Command operations 2.1. Definitions
The PRI field for SCSI command priority has been
added to the SCSI command PDU (see 5.1.1).
The Status Qualifier field has been added to the
SCSI response PDU (see 5.2.1).
Sense data may be returned (via autosense) for any
SCSI status, not just CHECK CONDITION (see 5.2.2).
Section 6: New Task Management Functions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
Four new task management functions (QUERY TASK, "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
QUERY TASK SET, I_T NEXUS RESET, and QUERY document are to be interpreted as described in [RFC2119].
ASYNCHRONOUS EVENT have been added (see 6.3).
A new "function succeeded" response has been added
(see 6.4.2).
Section 7: New Negotiation key 2.2. Acronyms
A new negotiation key has been added to enable the
use of the new features in section 5 and section 6.
3. Terminology Mapping ACA Auto Contingent Allegiance
AHS Additional Header Segment
ISID Initiator Session Identifier
LU Logical Unit
PDU Protocol Data Unit
SAM-5 SCSI Architecture Model - 5 (see [SAM5])
TSIH Target Session Identifying Handle
The iSCSI model (defined in [RFC-cons]) uses different 2.3. New Semantics
terminology than the SCSI Architecture Model. In some cases,
iSCSI uses multiple terms to describe what in the SCSI
Architecture Model is described with a single term. The iSCSI
terms and SAM-5 terms are not necessarily equivalent, but rather,
the iSCSI terms represent examples of the objects or classes
described in SAM-5 as follows:
-------------------------------------------------------- This document specifies new iSCSI semantics. This section summarizes
RFC EDITORS NOTE: The above reference to [RFC-cons] should the contents of the document.
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
+-----------------------------+---------------------------+ Section 3: The mapping of iSCSI objects to SAM-5 objects
| RFCxxx Terminology | SAM-5 Terminology | The iSCSI node may contain both initiator and target
+-----------------------------+---------------------------+ capabilities.
| Network Entity | none |
+-----------------------------+---------------------------+
| iSCSI Node | SCSI Device |
+-----------------------------+---------------------------+
| iSCSI Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Node Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Initiator Node | SCSI Initiator Device |
+-----------------------------+---------------------------+
| iSCSI Initiator Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Initiator Port | SCSI Initiator Port |
| Identifier; (i.e., iSCSI | Identifier |
| Node Name + ,,,i, + ISID)*1 | |
+-----------------------------+---------------------------+
| iSCSI Initiator Port Name; | SCSI Initiator Port Name |
| (i.e., iSCSI Node Name + | |
| ,,,i, + ISID)*1 | |
+-----------------------------+---------------------------+
| iSCSI Target Node | SCSI Target Device |
+-----------------------------+---------------------------+
| iSCSI Target Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Target Port | SCSI Target Port |
| Identifier; (i.e., iSCSI | Identifier |
| Node Name + ,,,t, + | |
| Target Portal Group Tag)*1 | |
+-----------------------------+---------------------------+
| iSCSI Target Port Name; | SCSI Target Port Name |
| (i.e., iSCSI Node Name + | |
| ,,,t, + Target Portal | |
| Group Tag)*1 | |
+-----------------------------+---------------------------+
| iSCSI Target Portal Group | SCSI Target Port |
+-----------------------------+---------------------------+
| iSCSI Initiator Name + | I_T Nexus Identifier |
| ',i,' + ISID + iSCSI | |
| Target Name + ',t,' + | |
| Target Portal Group Tag | |
+-----------------------------+---------------------------+
| Target Portal Group Tag | Relative Port ID |
+-----------------------------+---------------------------+
*1 The text encoding of the ISID value and the Target Portal Section 4: New feature use
Group Tag value includes an initial ,,0X or ,,0x (see [RFC- New features need negotiation for use. The
cons]). negotiation may have an impact on standard INQUIRY
data.
-------------------------------------------------------- Section 5: New command operations
RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx] The PRI field for SCSI command priority has been added
should reference this RFC, and this note should be removed. to the SCSI Command PDU (see Section 5.1.1). The
Status Qualifier field has been added to the SCSI
Response PDU (see Section 5.2.1). Sense data may be
returned (via Autosense) for any SCSI status, not just
CHECK CONDITION (see Section 5.2.2).
The above reference to [RFC-cons] should reference the RFC Section 6: New task management functions
number assigned to [draft-ietf-storm-iscsi-cons-xx], and this Four new task management functions (QUERY TASK, QUERY
note should be removed. TASK SET, I_T NEXUS RESET, and QUERY ASYNCHRONOUS
-------------------------------------------------------- EVENT) have been added (see Section 6.3). A new
"Function succeeded" response has been added (see
Section 6.4.2).
The following diagram shows an example of a combination target Section 7: New negotiation key
device and initiator device. Such a configuration may exist in a A new negotiation key has been added to enable the use
target device that implements a SCSI Copy Manager. This example of the new features in Sections 5 and 6.
shows how a session that shares Network Portals within a Portal
Group may be established (see Target Portal Group 1). In
addition, this example shows the Initiator using a different
Portal Group than the Target Portal Group, but the Initiator
Portal group sharing Network Portal A with the Target Portal
Group.
----------------------------IP Network--------------------- 3. Terminology Mapping
| | |
+----|---------------|-------+ +----|------------+
| +----------+ +----------+ | | +----------+ |
| | Network | | Network | | | | Network | |
| | Portal A | | Portal B | | | | Portal A | |
| +----------+ +----------+ | | +----------+ |
| | Target | | | | Initiator |
| | Portal | | | | Portal |
| | Group 1 | | | | Group 2 |
+----|---------------|-------+ +----|------------+
| | |
+----------|---------------|--------------------|--------------------+
| +--------|---------------|----+ +-------------|------------------+ |
| |+-------|---------------|---+| |+------------|-----------------+| |
| ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| |
| || || || || |
| || (TSIH = 56) || || (SSID = 48) || |
| |+---------------------------+| |+------------------------------+| |
| | | | | |
| | iSCSI Target Node | | iSCSI Initiator Node | |
| +-----------------------------+ +--------------------------------+ |
| iSCSI Node |
| (within Network Entity, not shown) |
+--------------------------------------------------------------------+
4. New Feature Use
4.1 Negotiation of New Feature Use The iSCSI model (defined in [RFC7143]) uses different terminology
than the SCSI Architecture Model. In some cases, iSCSI uses multiple
terms to describe what in the SCSI Architecture Model is described
with a single term. The iSCSI terms and SAM-5 terms are not
necessarily equivalent, but rather, the iSCSI terms represent
examples of the objects or classes described in SAM-5 as follows:
The iSCSIProtocolLevel operational text key (see 7.1.1) Terminology in RFC 7143 | Terminology in SAM-5
containing a value of "2" MUST be negotiated to enable the use of +-----------------------------+---------------------------+
features described in this RFC. | Network Entity | none |
+-----------------------------+---------------------------+
| iSCSI Node | SCSI Device |
+-----------------------------+---------------------------+
| iSCSI Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Node Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Initiator Node | SCSI Initiator Device |
+-----------------------------+---------------------------+
| iSCSI Initiator Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Initiator Port | SCSI Initiator Port |
| Identifier; (i.e., iSCSI | Identifier |
| Node Name + ,,,i, + ISID)** | |
+-----------------------------+---------------------------+
| iSCSI Initiator Port Name; | SCSI Initiator Port Name |
| (i.e., iSCSI Node Name + | |
| ,,,i, + ISID)** | |
+-----------------------------+---------------------------+
| iSCSI Target Node | SCSI Target Device |
+-----------------------------+---------------------------+
| iSCSI Target Name | SCSI Device Name |
+-----------------------------+---------------------------+
| iSCSI Target Port | SCSI Target Port |
| Identifier; (i.e., iSCSI | Identifier |
| Node Name + ,,,t, + | |
| Target Portal Group Tag)** | |
+-----------------------------+---------------------------+
| iSCSI Target Port Name; | SCSI Target Port Name |
| (i.e., iSCSI Node Name + | |
| ,,,t, + Target Portal | |
| Group Tag)** | |
+-----------------------------+---------------------------+
| iSCSI Target Portal Group | SCSI Target Port |
+-----------------------------+---------------------------+
| iSCSI Initiator Name + | I_T Nexus Identifier |
| ',i,' + ISID + iSCSI | |
| Target Name + ',t,' + | |
| Target Portal Group Tag | |
+-----------------------------+---------------------------+
| Target Portal Group Tag | Relative Port ID |
+-----------------------------+---------------------------+
This is an iSCSI negotiation mechanism that enabled iSCSI support ** The text encoding of the ISID value and the Target Portal Group
for corresponding SCSI capabilities (see [SAM5] and [SPC4]. For Tag value includes an initial ,,0X or ,,0x (see [RFC7143]).
this reason, negotiation of this key to a value of "2" is
necessary, but not sufficient for use of the SCSI capabilities
enabled by the iSCSI features in this RFC.
For example, an iSCSI implementation may negotiate this new key The following diagram shows an example of a combination target device
to "2" but respond to the new task management functions (see 6.3) and initiator device. Such a configuration may exist in a target
with a "Task management function not supported" (which indicates device that implements a SCSI Copy Manager. This example shows how a
a SCSI error that prevents the function from being performed). session that shares Network Portals within a Portal Group may be
In contrast, if the key is negotiated to "2", an iSCSI established (see Target Portal Group 1). In addition, this example
implementation MUST NOT reject a task management function request shows the initiator using a different portal group than the target
PDU that requests one of the new task management functions (as portal group, but the initiator portal group sharing Network Portal A
such a reject would report an iSCSI protocol error). with the target portal group.
4.2 Impact on standard INQUIRY data ----------------------------IP Network---------------------
| | |
+----|---------------|-------+ +----|------------+
| +----------+ +----------+ | | +----------+ |
| | Network | | Network | | | | Network | |
| | Portal A | | Portal B | | | | Portal A | |
| +----------+ +----------+ | | +----------+ |
| | Target | | | | Initiator |
| | Portal | | | | Portal |
| | Group 1 | | | | Group 2 |
+----|---------------|-------+ +----|------------+
| | |
+----------|---------------|--------------------|--------------------+
| +--------|---------------|----+ +-------------|------------------+ |
| |+-------|---------------|---+| |+------------|-----------------+| |
| ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| |
| || || || || |
| || (TSIH = 56) || || (SSID = 48) || |
| |+---------------------------+| |+------------------------------+| |
| | | | | |
| | iSCSI Target Node | | iSCSI Initiator Node | |
| +-----------------------------+ +--------------------------------+ |
| iSCSI Node |
| (within Network Entity, not shown) |
+--------------------------------------------------------------------+
The negotiated value of the iSCSIProtocolLevel key is an 4. New Feature Use
increment from the base iSCSI version descriptor value
(0960h)(see [SPC4]). If the SCSI device server returns an iSCSI
version descriptor in the standard INQUIRY data, then the value
returned in that iSCSI version descriptor MUST be set to the sum
of the base value (0960h) plus the negotiated value of the
iSCSIProtocolLevel key (for example, if the negotiated
iSCSIProtocolLevel=2, then if an iSCSI version descriptor is
returned in the standard INQUIRY data it is set to 0962h).
-------------------------------------------------------- 4.1. Negotiation of New Feature Use
RFC EDITORS NOTE: The specification text in this section
requires corresponding changes in a SCSI standard (SPC-4 or
SPC-5) that is developed by INCITS Technical Committee T10.
Confirmation that these T10 changes have been made is
necessary before publishing this draft as an RFC; the
contacts for obtaining this confirmation are the primary
draft author (Frederick Knight) and storm WG chair (David
Black).
--------------------------------------------------------
5. SCSI Commands The iSCSIProtocolLevel operational text key (see Section 7.1.1)
containing a value of "2" MUST be negotiated to enable the use of
features described in this RFC.
5.1 SCSI Command Additions This is an iSCSI negotiation mechanism that enabled iSCSI support for
corresponding SCSI capabilities (see [SAM5] and [SPC4]). For this
reason, negotiation of this key to a value of "2" is necessary but
not sufficient for use of the SCSI capabilities enabled by the iSCSI
features in this RFC.
The format of the SCSI Command PDU is: For example, an iSCSI implementation may negotiate this new key to
"2" but respond to the new task management functions (see Section
6.3) with "Task management function not supported" (which indicates a
SCSI error that prevents the function from being performed). In
contrast, if the key is negotiated to "2", an iSCSI implementation
MUST NOT reject a Task Management Function Request PDU that requests
one of the new task management functions (as such a reject would
report an iSCSI protocol error).
Byte/ 0 | 1 | 2 | 3 | 4.2. Impact on Standard INQUIRY Data - iSCSI Version Descriptors
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0|.|I| 0x01 |F|R|W|. .|ATTR | PRI | Reserved |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+
8| Logical Unit Number (LUN) |
+ +
12| |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| Expected Data Transfer Length |
+---------------+---------------+---------------+---------------+
24| CmdSN |
+---------------+---------------+---------------+---------------+
28| ExpStatSN |
+---------------+---------------+---------------+---------------+
32/ SCSI Command Descriptor Block (CDB) /
+/ /
+---------------+---------------+---------------+---------------+
48/ AHS (Optional) /
+---------------+---------------+---------------+---------------+
x/ Header Digest (Optional) /
+---------------+---------------+---------------+---------------+
y/ (DataSegment, Command Data) (Optional) /
+/ /
+---------------+---------------+---------------+---------------+
z/ Data Digest (Optional) /
+---------------+---------------+---------------+---------------+
The SCSI Command PDU above is duplicated from [RFC-cons] for The negotiated value of the iSCSIProtocolLevel key is an increment
reference to show the PRI field. For any field other than the from the base iSCSI version descriptor value (0960h); see [SPC4]. If
PRI field, the text in [RFC-cons] supersedes the text in section the SCSI device server returns an iSCSI version descriptor in the
5.1 of this document in the event the two documents conflict. standard INQUIRY data, then the value returned in that iSCSI version
descriptor MUST be set to the sum of the base value (0960h) plus the
negotiated value of the iSCSIProtocolLevel key. (For example, if the
negotiated iSCSIProtocolLevel=2, then if an iSCSI version descriptor
is returned in the standard INQUIRY data, it is set to 0962h.)
-------------------------------------------------------- In support of this functionality, INCITS Technical Committee T10,
RFC EDITORS NOTE: The above references to [RFC-cons] should which is responsible for SCSI standards, has assigned SCSI version
reference the RFC number assigned to [draft-ietf-storm-iscsi- descriptor codes 0961h-097Fh to RFC 7144 for IANA to manage via the
cons-xx], and this note should be removed. values 1-31 of the iSCSIProtocolLevel key; see Section 9. The "No
-------------------------------------------------------- version claimed" description for the value 0 of the
iSCSIProtocolLevel key corresponds to the existing T10 assignment of
the 0960h SCSI version descriptor code to "iSCSI (no version
claimed)" -- for this reason, the assignment of the value 0 in the
IANA registry for the iSCSIProtocolLevel key must not be changed.
5.1.1 Command Priority (byte 2) 5. SCSI Commands
The Command Priority (PRI) is a four (4) bit field that specifies 5.1. SCSI Command Additions
the relative scheduling importance of this command in relation to
other commands already in the task set with SIMPLE task
attributes(see [SAM5]).
Section 11, iSCSI PDU Formats of [RFC-cons], requires that The format of the SCSI Command PDU is:
senders set this field to zero. A sender MUST NOT set this field
to a value other than zero unless the iSCSIProtocolLevel text key
defined in section 7.1.1 has been negotiated on the session with
a value of "2".
-------------------------------------------------------- Byte/ 0 | 1 | 2 | 3 |
RFC EDITORS NOTE: The above reference to [RFC-cons] should / | | | |
reference the RFC number assigned to [draft-ietf-storm-iscsi- |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
cons-xx], and this note should be removed. +---------------+---------------+---------------+---------------+
-------------------------------------------------------- 0|.|I| 0x01 |F|R|W|. .|ATTR | PRI | Reserved |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+
8| Logical Unit Number (LUN) |
+ +
12| |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| Expected Data Transfer Length |
+---------------+---------------+---------------+---------------+
24| CmdSN |
+---------------+---------------+---------------+---------------+
28| ExpStatSN |
+---------------+---------------+---------------+---------------+
32/ SCSI Command Descriptor Block (CDB) /
+/ /
+---------------+---------------+---------------+---------------+
48/ AHS (Optional) /
+---------------+---------------+---------------+---------------+
x/ Header Digest (Optional) /
+---------------+---------------+---------------+---------------+
y/ (DataSegment, Command Data) (Optional) /
+/ /
+---------------+---------------+---------------+---------------+
z/ Data Digest (Optional) /
+---------------+---------------+---------------+---------------+
This field MUST be ignored by iSCSI targets unless the The SCSI Command PDU above is duplicated from [RFC7143] for reference
iSCSIProtocolLevel text key with a value of "2" as defined in to show the PRI field. For any field other than the PRI field, the
section 7.1.1 was negotiated on the session. text in [RFC7143] supersedes the text in Section 5.1 of this document
in the event the two documents conflict.
See [SAM5] for additional considerations on the use of the 5.1.1. Command Priority (Byte 2)
command priority field.
5.2 SCSI Response Additions The Command Priority (PRI) is a four-bit field that specifies the
relative scheduling importance of this command in relation to other
commands already in the task set with SIMPLE task attributes (see
[SAM5]).
The format of the SCSI Response PDU is: Section 11 ("iSCSI PDU Formats") of [RFC7143] requires that senders
set this field to zero. A sender MUST NOT set this field to a value
other than zero unless the iSCSIProtocolLevel text key defined in
Section 7.1.1 has been negotiated on the session with a value of "2".
Byte/ 0 | 1 | 2 | 3 | This field MUST be ignored by iSCSI targets unless the
/ | | | | iSCSIProtocolLevel text key with a value of "2" as defined in Section
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7| 7.1.1 was negotiated on the session.
+---------------+---------------+---------------+---------------+
0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+
8| Status Qualifier | Reserved |
+---------------+---------------+---------------+---------------+
12| Reserved |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| SNACK Tag or Reserved |
+---------------+---------------+---------------+---------------+
24| StatSN |
+---------------+---------------+---------------+---------------+
28| ExpCmdSN |
+---------------+---------------+---------------+---------------+
32| MaxCmdSN |
+---------------+---------------+---------------+---------------+
36| ExpDataSN or Reserved |
+---------------+---------------+---------------+---------------+
40| Bidirectional Read Residual Count or Reserved |
+---------------+---------------+---------------+---------------+
44| Residual Count or Reserved |
+---------------+---------------+---------------+---------------+
48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+
/ Data Segment (Optional) /
+/ /
+---------------+---------------+---------------+---------------+
| Data-Digest (Optional) |
+---------------+---------------+---------------+---------------+
The SCSI Response PDU above is duplicated from [RFC-cons] for See [SAM5] for additional considerations on the use of the Command
reference to show the Status Qualifier field. For any field Priority field.
other than the Status field, the Status Qualifier field, and the
Data Segment - Sense and Response Data Segment field, the text in
[RFC-cons] supersedes the text in section 5.2 of this document in
the event the two documents conflict.
-------------------------------------------------------- 5.2. SCSI Response Additions
RFC EDITORS NOTE: The above references to [RFC-cons] should
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
5.2.1 Status Qualifier The format of the SCSI Response PDU is:
The Status Qualifier provides additional status information (see Byte/ 0 | 1 | 2 | 3 |
[SAM5]). / | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+
8| Status Qualifier | Reserved |
+---------------+---------------+---------------+---------------+
12| Reserved |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| SNACK Tag or Reserved |
+---------------+---------------+---------------+---------------+
24| StatSN |
+---------------+---------------+---------------+---------------+
28| ExpCmdSN |
+---------------+---------------+---------------+---------------+
32| MaxCmdSN |
+---------------+---------------+---------------+---------------+
36| ExpDataSN or Reserved |
+---------------+---------------+---------------+---------------+
40| Bidirectional Read Residual Count or Reserved |
+---------------+---------------+---------------+---------------+
44| Residual Count or Reserved |
+---------------+---------------+---------------+---------------+
48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+
/ Data Segment (Optional) /
+/ /
+---------------+---------------+---------------+---------------+
| Data-Digest (Optional) |
+---------------+---------------+---------------+---------------+
As defined in Section 11, iSCSI PDU Formats of [RFC-cons], The SCSI Response PDU above is duplicated from [RFC7143] for
compliant senders already set this field to zero. Compliant reference to show the Status Qualifier field. For any field other
senders MUST NOT set this field to a value other than zero unless than the Status field, the Status Qualifier field, and the Data
the iSCSIProtocolLevel text key with a value of "2" as defined in Segment - Sense and Response Data Segment field, the text in
section 7.1.1 was negotiated on the session. [RFC7143] supersedes the text in Section 5.2 of this document in the
event the two documents conflict.
-------------------------------------------------------- 5.2.1. Status Qualifier
RFC EDITORS NOTE: The above reference to [RFC-cons] should
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
This field MUST be ignored by receivers unless the The Status Qualifier provides additional status information (see
iSCSIProtocolLevel text key with a value of "2" as defined in [SAM5]).
section 7.1.1 was negotiated on the session.
5.2.2 Data Segment - Sense and Response Data Segment As defined in Section 11 ("iSCSI PDU Formats") of [RFC7143],
compliant senders already set this field to zero. Compliant senders
MUST NOT set this field to a value other than zero unless the
iSCSIProtocolLevel text key with a value of "2" as defined in Section
7.1.1 was negotiated on the session.
Section 11.4.7 of [RFC-cons] specifies that iSCSI targets MUST This field MUST be ignored by receivers unless the iSCSIProtocolLevel
support and enable autosense. If Status is CHECK CONDITION text key with a value of "2" as defined in Section 7.1.1 was
(0x02), then the Data Segment MUST contain sense data for the negotiated on the session.
failed command. While [RFC-cons] does not make any statements
about the state of the Data Segment when the Status is not CHECK
CONDITION (0x02)(i.e., the Data Segment is not prohibited from
containing sense data when the Status is not CHECK CONDITION),
negotiation of the iSCSIProtocolLevel text key with a value of
"2" as defined in section 7.1.1 explicitly indicates that the
Data Segment MAY contain sense data at any time, no matter what
value is set in the Status field.
-------------------------------------------------------- 5.2.2. Data Segment - Sense and Response Data Segment
RFC EDITORS NOTE: The above references to [RFC-cons] should
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
6. Task Management Functions Section 11.4.7 of [RFC7143] specifies that iSCSI targets MUST support
and enable Autosense. If Status is CHECK CONDITION (0x02), then the
Data Segment MUST contain sense data for the failed command. While
[RFC7143] does not make any statements about the state of the Data
Segment when the Status is not CHECK CONDITION (0x02) (i.e., the Data
Segment is not prohibited from containing sense data when the Status
is not CHECK CONDITION), negotiation of the iSCSIProtocolLevel text
key with a value of "2" as defined in Section 7.1.1 explicitly
indicates that the Data Segment MAY contain sense data at any time,
no matter what value is set in the Status field.
6.1 Task Management Function Request PDU 6. Task Management Functions
Byte/ 0 | 1 | 2 | 3 | 6.1. Task Management Function Request PDU
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0|.|I| 0x02 |1| Function | Reserved |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+
8| Logical Unit Number (LUN) |
+ +
12| |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| Referenced Task Tag or 0xffffffff |
+---------------+---------------+---------------+---------------+
24| CmdSN |
+---------------+---------------+---------------+---------------+
28| ExpStatSN |
+---------------+---------------+---------------+---------------+
32| RefCmdSN or Reserved |
+---------------+---------------+---------------+---------------+
36| ExpDataSN or Reserved |
+---------------+---------------+---------------+---------------+
40| Reserved /
+/ /
+---------------+---------------+---------------+---------------+
48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+
The Task Management Function Request PDU above is duplicated from Byte/ 0 | 1 | 2 | 3 |
[RFC-cons] for reference only. [RFC-cons] supersedes the text in / | | | |
section 6.1 and 6.2 of this document in the event the two |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
documents conflict. +---------------+---------------+---------------+---------------+
0|.|I| 0x02 |1| Function | Reserved |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+
8| Logical Unit Number (LUN) |
+ +
12| |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| Referenced Task Tag or 0xffffffff |
+---------------+---------------+---------------+---------------+
24| CmdSN |
+---------------+---------------+---------------+---------------+
28| ExpStatSN |
+---------------+---------------+---------------+---------------+
32| RefCmdSN or Reserved |
+---------------+---------------+---------------+---------------+
36| ExpDataSN or Reserved |
+---------------+---------------+---------------+---------------+
40| Reserved /
+/ /
+---------------+---------------+---------------+---------------+
48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+
-------------------------------------------------------- The Task Management Function Request PDU above is duplicated from
RFC EDITORS NOTE: The above references to [RFC-cons] should [RFC7143] for reference only. [RFC7143] supersedes the text in
reference the RFC number assigned to [draft-ietf-storm-iscsi- Sections 6.1 and 6.2 of this document in the event the two documents
cons-xx], and this note should be removed. conflict.
--------------------------------------------------------
6.2 Existing Task Management Functions 6.2. Existing Task Management Functions
Section 11.5 of [RFC-cons] defines the semantics used to request Section 11.5 of [RFC7143] defines the semantics used to request that
SCSI Task Management Functions be performed. The following task SCSI task management functions be performed. The following task
management functions are defined: management functions are defined:
1 - ABORT TASK 1 - ABORT TASK
2 - ABORT TASK SET 2 - ABORT TASK SET
3 - CLEAR ACA 3 - CLEAR ACA
4 - CLEAR TASK SET 4 - CLEAR TASK SET
5 - LOGICAL UNIT RESET 5 - LOGICAL UNIT RESET
6 - TARGET WARM RESET 6 - TARGET WARM RESET
7 - TARGET COLD RESET 7 - TARGET COLD RESET
8 - TASK REASSIGN 8 - TASK REASSIGN
-------------------------------------------------------- 6.3. Task Management Function Additions
RFC EDITORS NOTE: The above references to [RFC-cons] should
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
6.3 Task Management Function Additions
Additional task Management function codes are listed below. For
a more detailed description of SCSI task management, see [SAM5].
9 - QUERY TASK - determines if the command identified by the
Referenced Task Tag field is present in the task set.
10 - QUERY TASK SET - determine if any command is present in
the task set for the I_T_L Nexus on which the task management
function was received.
11 - I_T NEXUS RESET - perform an I_T nexus loss function (see
[SAM5]) for the I_T nexus on which the task management
function was received.
12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit
attention condition or a deferred error pending for the I_T_L
nexus on which the task management function was received.
These task management function requests MUST NOT be sent unless
the iSCSIProtocolLevel text key with a value of "2" as defined in
section 7.1.1 was negotiated on the session.
Any compliant initiator that sends any of the new task management Additional task management function codes are listed below. For a
functions defined in this section MUST also support all new task more detailed description of SCSI task management, see [SAM5].
management function responses (as specified in section 6.4.2).
For all of the task management functions detailed in this 9 - QUERY TASK - determine if the command identified by the
section, the Task Management function response MUST be returned Referenced Task Tag field is present in the task set.
as detailed in section 6.4.
The iSCSI target MUST ensure that no responses for the commands 10 - QUERY TASK SET - determine if any command is present in the
covered by a task management function are sent to the iSCSI task set for the I_T_L Nexus on which the task management
initiator port after the Task Management response except for a function was received.
commands covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK
SET.
If a QUERY TASK is issued for a task created by an immediate 11 - I_T NEXUS RESET - perform an I_T nexus loss function (see
command then RefCmdSN MUST be that of the Task Management request [SAM5]) for the I_T nexus on which the task management function
itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN was received.
MUST be set to the CmdSN of the task to be queried (lower than
CmdSN).
If the connection is still active (it is not undergoing an 12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit
implicit or explicit logout), QUERY TASK MUST be issued on the attention condition or a deferred error pending for the I_T_L
same connection to which the task to be queried is allegiant at nexus on which the task management function was received.
the time the Task Management request is issued. If the
connection is implicitly or explicitly logged out (i.e., no other
request will be issued on the failing connection and no other
response will be received on the failing connection), then a
QUERY TASK function request may be issued on another connection.
This Task Management request will then establish a new allegiance
for the command being queried.
At the target a QUERY TASK function MUST NOT be executed on a These task management function requests MUST NOT be sent unless the
Task Management request; such a request MUST result in Task iSCSIProtocolLevel text key with a value of "2" as defined in Section
Management response of "Function rejected". 7.1.1 was negotiated on the session.
For the I_T NEXUS RESET function, the target device MUST respond Any compliant initiator that sends any of the new task management
to the function as defined in [SAM5]. Each logical unit functions defined in this section MUST also support all new task
accessible via the receiving I_T NEXUS MUST behave as dictated by management function responses (as specified in Section 6.4.2).
the I_T nexus loss function in [SAM5] for the I_T nexus on which
the task management function was received. The target device
MUST drop all connections in the session over which this function
is received. Independent of the DefaultTime2Wait and
DefaultTime2Retain value applicable to the session over which
this function is received, the target device MUST consider each
participating connection in the session to have immediately timed
out, leading to FREE state. The resulting timeouts cause the
session timeout event defined in [RFC-cons], which in turn
triggers the I_T nexus loss notification to the SCSI layer as
described in [RFC-cons].
-------------------------------------------------------- For all of the task management functions detailed in this section,
RFC EDITORS NOTE: The above references to [RFC-cons] should the Task Management Function Response MUST be returned as detailed in
reference the RFC number assigned to [draft-ietf-storm-iscsi- Section 6.4.
cons-xx], and this note should be removed.
--------------------------------------------------------
6.3.1 LUN field The iSCSI target MUST ensure that no responses for the commands
covered by a task management function are sent to the iSCSI initiator
port after the Task Management response except for commands covered
by a TASK REASSIGN, QUERY TASK, or QUERY TASK SET.
This field is required for functions that address a specific LU If a QUERY TASK is issued for a task created by an immediate command,
(i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA, then RefCmdSN MUST be that of the Task Management request itself
LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY (i.e., CmdSN and RefCmdSN are equal); otherwise, RefCmdSN MUST be set
ASYNCHRONOUS EVENT) and is reserved in all others. to the CmdSN of the task to be queried (lower than CmdSN).
6.3.2 Referenced Task Tag If the connection is still active (it is not undergoing an implicit
The Initiator Task Tag of the task to be aborted for the ABORT or explicit logout), QUERY TASK MUST be issued on the same connection
TASK function, reassigned for the TASK REASSIGN function, or to which the task to be queried is allegiant at the time the Task
queried for the QUERY TASK function. For all other functions Management request is issued. If the connection is implicitly or
this field MUST be set to the reserved value 0xffffffff. explicitly logged out (i.e., no other request will be issued on the
failing connection and no other response will be received on the
failing connection), then a QUERY TASK function request may be issued
on another connection. This Task Management request will then
establish a new allegiance for the command being queried.
6.3.3 RefCmdSN At the target, a QUERY TASK function MUST NOT be executed on a Task
Management request; such a request MUST result in Task Management
response of "Function rejected".
If a QUERY TASK is issued for a task created by an immediate For the I_T NEXUS RESET function, the target device MUST respond to
command then RefCmdSN MUST be that of the Task Management request the function as defined in [SAM5]. Each logical unit accessible via
itself (i.e., CmdSN and RefCmdSN are equal). the receiving I_T NEXUS MUST behave as dictated by the I_T nexus loss
function in [SAM5] for the I_T nexus on which the task management
function was received. The target device MUST drop all connections
in the session over which this function is received. Independent of
the DefaultTime2Wait and DefaultTime2Retain values applicable to the
session over which this function is received, the target device MUST
consider each participating connection in the session to have
immediately timed out, leading to FREE state. The resulting timeouts
cause the session timeout event defined in [RFC7143], which in turn
triggers the I_T nexus loss notification to the SCSI layer as
described in [RFC7143].
For a QUERY TASK of a task created by non-immediate command 6.3.1. LUN Field
RefCmdSN MUST be set to the CmdSN of the task identified by the
Referenced Task Tag field. Targets must use this field as
described in section 11.6.1 of [RFC-cons] when the task
identified by the Referenced Task Tag field is not in the task
set.
-------------------------------------------------------- This field is required for functions that address a specific LU
RFC EDITORS NOTE: The above references to [RFC-cons] should (i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA, LOGICAL
reference the RFC number assigned to [draft-ietf-storm-iscsi- UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY ASYNCHRONOUS EVENT)
cons-xx], and this note should be removed. and is reserved in all others.
--------------------------------------------------------
6.4 Task Management Function Responses 6.3.2. Referenced Task Tag
6.4.1 Task Management Function Response PDU The Reference Task Tag is the Initiator Task Tag of the task to be
aborted for the ABORT TASK function, reassigned for the TASK REASSIGN
function, or queried for the QUERY TASK function. For all other
functions, this field MUST be set to the reserved value 0xffffffff.
Byte/ 0 | 1 | 2 | 3 | 6.3.3. RefCmdSN
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0|.|.| 0x22 |1| Reserved | Response | Reserved |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+-----------------------------------------------+---------------+
8| Additional Response Information | Reserved |
+-----------------------------------------------+---------------+
12| Reserved |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| Reserved |
+---------------+---------------+---------------+---------------+
24| StatSN |
+---------------+---------------+---------------+---------------+
28| ExpCmdSN |
+---------------+---------------+---------------+---------------+
32| MaxCmdSN |
+---------------+---------------+---------------+---------------+
36/ Reserved /
+/ /
+---------------+---------------+---------------+---------------+
48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+
Section 11.6 of [RFC-cons] defines the semantics used for If a QUERY TASK is issued for a task created by an immediate command
responses to SCSI Task Management Functions. The following then RefCmdSN MUST be that of the Task Management request itself
responses are defined in [RFC-cons]: (i.e., CmdSN and RefCmdSN are equal).
0 - Function Complete. For a QUERY TASK of a task created by non-immediate command RefCmdSN
1 - Task does not exist. MUST be set to the CmdSN of the task identified by the Referenced
2 - LUN does not exist. Task Tag field. Targets must use this field as described in section
3 - Task still allegiant. 11.6.1 of [RFC7143] when the task identified by the Referenced Task
4 - Task allegiance reassignment not supported. Tag field is not in the task set.
5 - Task management function not supported.
6 - Function authorization failed.
255 - Function rejected.
The Task Management Function Response PDU above and the list of 6.4. Task Management Function Responses
task management function responses above are duplicated from
[RFC-cons] for reference only. [RFC-cons] supersedes the text in
section 6.4.1 of this document in the event the two documents
conflict.
-------------------------------------------------------- 6.4.1. Task Management Function Response PDU
RFC EDITORS NOTE: The above references to [RFC-cons] should
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
Responses to new task management functions (see 6.4.2) are listed Byte/ 0 | 1 | 2 | 3 |
below. In addition, a new task Management response is listed / | | | |
below. For a more detailed description of SCSI task management |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
responses, see [SAM5]. +---------------+---------------+---------------+---------------+
0|.|.| 0x22 |1| Reserved | Response | Reserved |
+---------------+---------------+---------------+---------------+
4|TotalAHSLength | DataSegmentLength |
+-----------------------------------------------+---------------+
8| Additional Response Information | Reserved |
+-----------------------------------------------+---------------+
12| Reserved |
+---------------+---------------+---------------+---------------+
16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+
20| Reserved |
+---------------+---------------+---------------+---------------+
24| StatSN |
+---------------+---------------+---------------+---------------+
28| ExpCmdSN |
+---------------+---------------+---------------+---------------+
32| MaxCmdSN |
+---------------+---------------+---------------+---------------+
36/ Reserved /
+/ /
+---------------+---------------+---------------+---------------+
48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+
For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, Section 11.6 of [RFC7143] defines the semantics used for responses to
and QUERY ASYNCHRONOUS EVENT, the target performs the requested SCSI task management functions. The following responses are defined
Task Management function and sends a Task Management response in [RFC7143]:
back to the initiator.
6.4.2 Task Management Function Response Additions 0 - Function Complete
1 - Task does not exist
2 - LUN does not exist
3 - Task still allegiant
4 - Task allegiance reassignment not supported
5 - Task management function not supported
6 - Function authorization failed
255 - Function rejected
The new response is listed below: The Task Management Function Response PDU above and the list of task
management function responses above are duplicated from [RFC7143] for
reference only. [RFC7143] supersedes the text in section 6.4.1 of
this document in the event the two documents conflict.
7 - Function succeeded. Responses to new task management functions (see Section 6.4.2) are
listed below. In addition, a new task Management response is listed
below. For a more detailed description of SCSI task management
responses, see [SAM5].
In symbolic terms Response value 7 maps to the SCSI service For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, and
response of FUNCTION SUCCEEDED in [SAM5]. QUERY ASYNCHRONOUS EVENT, the target performs the requested Task
Management function and sends a Task Management response back to the
initiator.
The task management function response of "Function succeeded" 6.4.2. Task Management Function Response Additions
MUST be supported by an initiator that sends any of the new task
management functions (see 6.3).
For the QUERY TASK function, if the specified task is in the task The new response is listed below:
set, then the logical unit returns a Response value of Function
succeeded and additional response information is returned as
specified in [SAM5]. If the specified task is not in the task
set, then the logical unit returns a Response value of Function
complete.
For the QUERY TASK SET function, if there is any command present 7 - Function succeeded
in the task set from the specified I_T_L nexus, then the logical
unit returns a Response value of Function succeeded. If there
are no commands present in the task set from the specified I_T_L
nexus, then the logical unit returns a Response value of Function
complete.
For the I_T NEXUS RESET function, after completion of the events In symbolic terms Response value 7 maps to the SCSI service response
described in section 6.3 for this function, the logical unit of FUNCTION SUCCEEDED in [SAM5].
returns a Response value of Function complete. However, because
the target drops all connections, the Service Response (defined
by [SAM5]) for this SCSI task management function may not be
reliably delivered to the issuing initiator port.
For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention The Task Management Function Response of "Function succeeded" MUST be
condition or deferred error pending for the specified I_T_L supported by an initiator that sends any of the new task management
nexus, then the logical unit returns a Response value of Function functions (see Section 6.3).
succeeded and additional response information is returned as
specified in [SAM5]. If there is no unit attention or deferred
error pending for the specified I_T_L nexus then the logical unit
returns a Response value of Function complete.
6.5 Task Management Requests Affecting Multiple Tasks For the QUERY TASK function, if the specified task is in the task
set, then the logical unit returns a Response value of "Function
succeeded", and additional response information is returned as
specified in [SAM5]. If the specified task is not in the task set,
then the logical unit returns a Response value of "Function
complete".
Section 4.1 of [RFC5048] defines the notion of "affected tasks" For the QUERY TASK SET function, if there is any command present in
in multi-task abort scenarios. This section adds to the list the task set from the specified I_T_L nexus, then the logical unit
include in that section by defining the tasks affected by the I_T returns a Response value of "Function succeeded". If there are no
NEXUS RESET function. commands present in the task set from the specified I_T_L nexus, then
the logical unit returns a Response value of "Function complete".
I_T NEXUS RESET: All outstanding tasks received on the I_T For the I_T NEXUS RESET function, after completion of the events
nexus on which the function request was received for all described in Section 6.3 for this function, the logical unit returns
logical units accessible to the I_T nexus. a Response value of "Function complete". However, because the target
drops all connections, the Service Response (defined by [SAM5]) for
this SCSI task management function may not be reliably delivered to
the issuing initiator port.
Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048] For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention
identify semantics for task management functions that involve condition or deferred error pending for the specified I_T_L nexus,
multi-task abort operations. If an iSCSI implementation supports then the logical unit returns a Response value of "Function
the I_T NEXUS RESET function, it MUST also support the protocol succeeded", and additional response information is returned as
behavior as defined in those sections and follow the sequence of specified in [SAM5]. If there is no unit attention or deferred error
actions as described in those sections when processing the I_T pending for the specified I_T_L nexus, then the logical unit returns
NEXUS RESET function. a Response value of "Function complete".
7. Login/Text Operational Text Keys 6.5. Task Management Requests Affecting Multiple Tasks
7.1 New Operational Text Keys Section 4.1 of [RFC5048] defines the notion of "affected tasks" in
multi-task abort scenarios. This section adds to the list included
in that section by defining the tasks affected by the I_T NEXUS RESET
function.
7.1.1 iSCSIProtocolLevel I_T NEXUS RESET: All outstanding tasks received on the I_T nexus
on which the function request was received for all logical
units accessible to the I_T nexus.
Use: LO, IO Sections 4.1.2 and 4.1.3 of [RFC5048] identify semantics for task
Irrelevant when: SessionType = Discovery management functions that involve multi-task abort operations. If an
Senders: Initiator and Target iSCSI implementation supports the I_T NEXUS RESET function, it MUST
Scope: SW also support the protocol behavior as defined in those sections and
follow the sequence of actions as described in those sections when
processing the I_T NEXUS RESET function.
iSCSIProtocolLevel=<numerical-value-from-0-to-31> 7. Login/Text Operational Text Keys
Default is 1. 7.1. New Operational Text Keys
Result function is Minimum.
This key is used to negotiate the use of iSCSI features that 7.1.1. iSCSIProtocolLevel
require different levels of protocol support (e.g., PDU formats,
end node semantics) for proper operation.
Negotiation of the iSCSIProtocolLevel key to a value Use: LO, IO
corresponding to an RFC indicates that both negotiating parties Irrelevant when: SessionType = Discovery
are compliant to the RFC in question, and agree to support the Senders: Initiator and Target
corresponding PDU formats and semantics on that iSCSI session. Scope: SW
Features using this key are expected to be cumulative.
An iSCSIProtocolLevel key negotiated to "0" indicates that the iSCSIProtocolLevel=<numerical-value-from-0-to-31>
implementation does not claim a specific iSCSI protocol level.
An iSCSIProtocolLevel key negotiated to "1" indicates that the Default is 1.
implementation claims compliance with [RFC-cons]. Result function is Minimum.
-------------------------------------------------------- This key is used to negotiate the use of iSCSI features that require
RFC EDITORS NOTE: The above reference to [RFC-cons] should different levels of protocol support (e.g., PDU formats, end-node
reference the RFC number assigned to [draft-ietf-storm-iscsi- semantics) for proper operation.
cons-xx], and this note should be removed.
--------------------------------------------------------
An iSCSIProtocolLevel key negotiated to "2" is required to enable Negotiation of the iSCSIProtocolLevel key to a value corresponding to
use of features defined in this RFC. an RFC indicates that both negotiating parties are compliant to the
RFC in question and agree to support the corresponding PDU formats
and semantics on that iSCSI session. Features using this key are
expected to be cumulative.
If the negotiation answer is ignored by the acceptor, or the An iSCSIProtocolLevel key negotiated to "0" indicates that the
answer from the remote iSCSI end point is key=NotUnderstood, then implementation does not claim a specific iSCSI protocol level.
the features defined in this RFC, and the features defined in any
RFC requiring a key value greater than "2" MUST NOT be used.
8. Security Considerations An iSCSIProtocolLevel key negotiated to "1" indicates that the
implementation claims compliance with [RFC7143].
Command priorities are relative values, not absolute values (see An iSCSIProtocolLevel key negotiated to "2" is required to enable use
[SAM5] and affect collections of commands, not necessarily of features defined in this RFC.
individual commands (see [SAM5]); if command priority is
supported, it should be implemented in a fashion that avoids
unwanted reduction or denial of service.
All the iSCSI-related security text in [RFC3723] and the security If the negotiation answer is ignored by the acceptor, or the answer
text in [RFC-cons] is also directly applicable to this document. from the remote iSCSI end point is key=NotUnderstood, then the
features defined in this RFC, and the features defined in any RFC
requiring a key value greater than "2", MUST NOT be used.
-------------------------------------------------------- 8. Security Considerations
RFC EDITORS NOTE: The above reference to [RFC-cons] should
reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
9. IANA Considerations Command priorities are relative values, not absolute values (see
[SAM5], and affect collections of commands, not necessarily
individual commands (see [SAM5]). If command priority is supported,
it should be implemented in a fashion that avoids unwanted reduction
or denial of service.
This document modifies or creates a number of iSCSI-related All the iSCSI-related security text in [RFC3723] is directly
registries. The following iSCSI-related registries are modified: applicable to this document. The security text in [RFC7143] is
directly applicable as well.
1. iSCSI Task Management Functions Codes 9. IANA Considerations
Name of the existing registry: "iSCSI Task Management Function This document modifies or creates a number of iSCSI-related
Codes" registries.
Additional entries: The following iSCSI-related registries are modified.
9, QUERY TASK, [RFCxxx] 1. iSCSI Task Management Functions Codes
10, QUERY TASK SET, [RFCxxx] Name of the existing registry: "iSCSI Task Management Function
Codes"
11, I_T NEXUS RESET, [RFCxxx] The following entries have been added:
12, QUERY ASYNCHRONOUS EVENT, [RFCxxx] 9 - QUERY TASK, RFC 7144
13-127, Unassigned, [RFCxxx] 10 - QUERY TASK SET, RFC 7144
--------------------------------------------------------- 11 - I_T NEXUS RESET, RFC 7144
RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed. The last
entry (values 13-127 in the above list) should replace the
existing entry for the "Unassigned" values.
---------------------------------------------------------
2. iSCSI Login/Text Keys 12 - QUERY ASYNCHRONOUS EVENT, RFC 7144
Name of the existing registry: "iSCSI Login/Text Keys" 13-127 - Unassigned
Fields to record in the registry: Assigned value and its 2. iSCSI Login/Text Keys
associated RFC reference:
iSCSIProtocolLevel, [RFCxxx] Name of the existing registry: "iSCSI Login/Text Keys"
--------------------------------------------------------- Fields to record in the registry: Assigned value and its
RFC EDITORS NOTE: The above references to [RFCxxx] should associated RFC reference.
reference this RFC, and this note should be removed.
---------------------------------------------------------
This document creates the following iSCSI-related registries for The following entry has been added:
IANA to manage.
3. iSCSI Protocol Level iSCSIProtocolLevel, RFC 7144
Name of new registry: "iSCSI Protocol Level" IANA has created the following iSCSI-related registries.
Namespace details: Numerical values from 0 to 31 3. iSCSI Protocol Level
Information that must be provided to assign a new value: An Name of new registry: "iSCSI Protocol Level"
IESG-approved standards track specification defining the
semantics and interoperability requirements of the proposed
new value and the fields to be recorded in the registry.
Assignment policy: Namespace details: Numerical values from 0 to 31
The assignments of these values must be coordinated with the Information that must be provided to assign a new value: An IESG-
INCITS T10 committee; therefore review by an expert that approved Standards Track specification defining the semantics and
maintains an association with that committee is required prior interoperability requirements of the proposed new value and the
to IESG approval of the associated specification. After fields to be recorded in the registry.
creation of the registry, values are to be assigned
sequentially (for example, any value greater than 4 will not
be assigned until after the value 4 has been assigned).
Special care must be taken in the assignment of new values in Assignment policy:
this registry. Compatibility and interoperability will be
adversely impacted if proper care is not exercised. Features
using this key are expected to be cumulative. For example,
since this draft explicitly lists only value 2 for the
features listed in this draft, it is expected that a new RFC
assigning value 3 will also have the features listed in this
RFC and therefore such an RFC is expected to either revise or
replace this RFC. Assignments that do not follow this policy
should be reviewed and approved by the INCITS T10 committee.
3-31: range available to IANA for assignment in this registry. The assignments of these values must be coordinated with the
INCITS T10 committee; therefore, review by an expert that
maintains an association with that committee is required prior to
IESG approval of the associated specification. After creation of
the registry, values are to be assigned sequentially (for example,
any value greater than 4 will not be assigned until after the
value 4 has been assigned).
Fields to record in the registry: Assigned value, description, Special care must be taken in the assignment of new values in this
and its associated RFC reference. registry. Compatibility and interoperability will be adversely
impacted if proper care is not exercised. Features using this key
are expected to be cumulative. For example, since this document
explicitly lists only value 2 for the features listed in this
document, it is expected that a new RFC assigning value 3 will
also have the features listed in this RFC, and therefore such an
RFC is expected to either revise or replace this RFC. Assignments
that do not follow this policy should be reviewed and approved by
the INCITS T10 committee.
0, No version claimed, [RFCxxx] 3-31: range available to IANA for assignment in this registry.
1, RFC-cons, [RFCxxx] Fields to record in the registry: Assigned value, description, and
its associated RFC reference.
2, RFCxxx, [RFCxxx] The following entries have been added:
3-31, Unassigned Value Description Reference
--------------------------------------------------------- 0 No version claimed RFC 7144
RFC EDITORS NOTE: The above references to [RFCxxx] should
reference this RFC, and this note should be removed. The
above reference to RFC-cons should be replaced with the name
of the [draft-ietf-storm-iscsi-cons-xx] document, and this
note should be removed. All associated RFC references are to
this document; even the reference for value 1. The
description for value 1 however contains the RFC-cons name but
should not have [] around the description (it is a description
not a formal reference). The description for value 2 is the
name of this RFC but should not contain the [] (again, a
description not a formal reference). This note should be
removed.
---------------------------------------------------------
Allocation Policy: 1 RFC 7143 [RFC7143]
Expert review ([IANA]) and Standards Action ([IANA]) 2 RFC 7144 RFC 7144
4. iSCSI Task Management Function Response Codes 3-31 Unassigned
Name of new registry: "iSCSI Task Management Function Response Allocation Policy: Expert Review and Standards Action [RFC5226]
Codes"
Namespace details: Numerical values that can fit in 8 bits. 4. iSCSI Task Management Function Response Codes
Information that must be provided to assign a new value: An Name of new registry: "iSCSI Task Management Function Response
IESG-approved specification defining the semantics and Codes"
interoperability requirements of the proposed new value and
the fields to be recorded in the registry.
Assignment policy: Namespace details: Numerical values that can fit in 8 bits.
If the requested value is not already assigned, it may be Information that must be provided to assign a new value: An IESG-
assigned to the requester. approved specification defining the semantics and interoperability
requirements of the proposed new value and the fields to be
recorded in the registry.
8-254: Range available to IANA for assignment in this Assignment policy:
registry.
Fields to record in the registry: Assigned value, Operation If the requested value is not already assigned, it may be assigned
Name, and its associated RFC reference. to the requester.
0, Function complete, [RFC-cons] 8-254: Range available to IANA for assignment in this registry.
1, Task does not exist, [RFC-cons] Fields to record in the registry: Assigned value, Operation Name,
and its associated RFC reference.
2, LUN does not exist, [RFC-cons] The following entries have been added:
3, Task still allegiant, [RFC-cons] 0 - Function complete, [RFC7143]
4, Task allegiance reassignment not supported, [RFC-cons] 1 - Task does not exist, [RFC7143]
5, Task management function not supported, [RFC-cons] 2 - LUN does not exist, [RFC7143]
6, Function authorization failed, [RFC-cons] 3 - Task still allegiant, [RFC7143]
7, Function succeeded, [RFCxxx] 4 - Task allegiance reassignment not supported, [RFC7143]
8-254, Unassigned 5 - Task management function not supported, [RFC7143]
255, Function rejected, [RFC-cons] 6 - Function authorization failed, [RFC7143]
------------------------------------------------------------ 7 - Function succeeded, RFC 7144
RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed.
The above references to [RFC-cons] should reference the 8-254 - Unassigned
[draft-ietf-storm-iscsi-cons-xx] document, and this note
should be removed.
------------------------------------------------------------
Allocation Policy: 255 - Function rejected, [RFC7143]
Standards Action ([IANA]) Allocation Policy: Standards Action [RFC5226]
10. References 10. References
10.1 Normative References 10.1. Normative References
[RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and [RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and F.
Travostino, F., "Securing Block Storage Protocols Travostino, "Securing Block Storage Protocols over IP",
over IP", RFC 3723, April 2004. RFC 3723, April 2004.
[RFC5048] Chadalapaka, M., "Internet Small Computer System [RFC5048] Chadalapaka, M., Ed., "Internet Small Computer System
Interface (iSCSI) Corrections and Clarifications", Interface (iSCSI) Corrections and Clarifications", RFC
RFC 5048, October 2007. 5048, October 2007.
[draft-ietf-storm-iscsi-cons-xx] Chadalapaka, M., Satran, J., [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
Kalman, M., "iSCSI Protocol (consolidated)", RFC xxx, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
Date 2013. May 2008.
------------------------------------------------------------ [RFC7143] Chadalapaka, M., Satran, J., Meth, K., and D. Black,
RFC EDITORS NOTE: The above references to [draft-ietf-storm- "Internet Small Computer System Interface (iSCSI) Protocol
iscsi-cons-xx] and RFC xxx should reference the RFC number (Consolidated)", RFC 7143, April 2014.
assigned to that draft, and this note should be removed.
------------------------------------------------------------
[IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing [SAM2] INCITS Technical Committee T10, "SCSI Architecture Model -
an IANA Considerations Section in RFCs", BCP 26, RFC 2 (SAM-2)", ANSI INCITS 366-2003, ISO/IEC 14776-412, 2003.
5226, May 2008.
[SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2). [SAM5] INCITS Technical Committee T10, "SCSI Architecture Model -
5 (SAM-5)", T10/BSR INCITS 515 rev 04, Committee Draft.
[SAM5] T10/2104D rev r04, SCSI Architecture Model - 5 (SAM- [SPC4] INCITS Technical Committee T10, "SCSI Primary Commands -
5), Committee Draft. 4", ANSI INCITS 513-201x.
[SPC4] T10/1731D rev r36, SCSI Primary Commands - 4 (SPC-4), 10.2. Informative References
Committee Draft.
10.2 Informative References [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, 11. Acknowledgements
M., and E. Zeidner, "Internet Small Computer Systems
Interface (iSCSI)", RFC 3720, April 2004.
10.3 Additional Reference Sources The Storage Maintenance (STORM) Working Group in the Transport Area
of the IETF has been responsible for defining these additions to the
iSCSI protocol (apart from other relevant IP Storage protocols). The
authors acknowledge the contributions of the entire working group and
other IETF reviewers.
For more information on the SCSI Architecture Model and SCSI The following individuals directly contributed to identifying issues
Primary Commands - 4, contact the INCITS T10 Technical Committee and/or suggesting resolutions to the issues clarified in this
for SCSI Storage Interfaces at http://www.t10.org. document: David Black, Rob Elliott. This document benefited from all
of these contributions.
11. Acknowledgements Authors' Addresses
The Storage Maintenance (STORM) Working Group in the Transport Frederick Knight
Area of the IETF has been responsible for defining these 7301 Kit Creek Road
additions to the iSCSI protocol (apart from other relevant IP P.O. Box 13917
Storage protocols). The editor acknowledges the contributions of Research Triangle Park, NC 27709
the entire working group and other IETF reviewers. USA
The following individuals directly contributed to identifying Phone: +1-919-476-5362
[RFCxxx] issues and/or suggesting resolutions to the issues EMail: knight@netapp.com
clarified in this document: David Black, Rob Elliott. This
document benefited from all of these contributions.
------------------------------------------------------------
RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed.
------------------------------------------------------------
Author's Addresses: Mallikarjun Chadalapaka
Frederick Knight Microsoft
7301 Kit Creek Road One Microsoft Way
P.O. Box 13917 Redmond, WA 98052
Research Triangle Park, NC 27709, USA USA
Phone: +1-919-476-5362
Email: knight@netapp.com
Mallikarjun Chadalapaka EMail: cbm@chadalapaka.com
Microsoft
One Microsoft Way
Redmond, WA 98052 USA
Email: cbm@chadalapaka.com
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