draft-ietf-storm-iscsi-sam-06.txt   draft-ietf-storm-iscsi-sam-07.txt 
Storage Maintenance (StorM) Working Group Frederick Knight Storage Maintenance (StorM) Working Group Frederick Knight
Internet Draft NetApp Internet Draft NetApp
Intended status: Standards Track M. Chadalapaka Intended status: Standards Track M. Chadalapaka
Expires: January 2013 Microsoft Expires: December 2013 Microsoft
July 2012 June 2013
Internet Small Computer Systems Interface (iSCSI) SCSI Features Internet Small Computer Systems Interface (iSCSI) SCSI Features
Update Update
draft-ietf-storm-iscsi-sam-06.txt draft-ietf-storm-iscsi-sam-07.txt
Abstract Abstract
Internet Small Computer Systems Interface (iSCSI) is a SCSI Internet Small Computer Systems Interface (iSCSI) is a SCSI
transport protocol that maps the SCSI family of protocols onto transport protocol that maps the SCSI family of protocols onto
TCP/IP. The iSCSI protocol as specified in [draft-ietf-storm- TCP/IP. The iSCSI protocol as specified in [draft-ietf-storm-
iscsi-cons-xx] (and as previously specified by the combination iscsi-cons-xx] (and as previously specified by the combination
of RFC 3720 and RFC 5048) is based on the SAM-2 (SCSI of RFC 3720 and RFC 5048) is based on the SAM-2 (SCSI
Architecture Model - 2) version of the SCSI family of Architecture Model - 2) version of the SCSI family of
protocols. This document defines enhancements to the iSCSI protocols. This document defines enhancements to the iSCSI
protocol to support certain additional features of the SCSI protocol to support certain additional features of the SCSI
protocol that were defined in SAM-3, SAM-4, and SAM-5. protocol that were defined in SAM-3, SAM-4, and SAM-5.
This document is a companion document to [draft-ietf-storm- This document is a companion document to [draft-ietf-storm-
iscsi-cons-xx]. iscsi-cons-xx].
-------------------------------------------------------- --------------------------------------------------------
RFC EDITORS NOTE: The above references to [draft-ietf-storm- RFC EDITORS NOTE: The above references to [draft-ietf-storm-
iscsi-cons-xx] should reference the RFC number assigned to iscsi-cons-xx] should reference the RFC number assigned to
that document, and this note should be removed. that document, and this note should be removed.
-------------------------------------------------------- --------------------------------------------------------
Status of this Memo Status of this Memo
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the provisions of BCP 78 and BCP 79. the provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire January, 2013. This Internet-Draft will expire December, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2013 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. without warranty as described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction.................................................. 3 1. Introduction.................................................... 3
2. Definitions, Acronyms, and Document Summary................... 3 2. Definitions, Acronyms, and Document Summary..................... 3
2.1 Definitions ............................................ 3 2.1 Definitions ............................................. 3
2.2 Acronyms ............................................... 3 2.2 Acronyms ................................................ 3
2.3 New Semantics .......................................... 3 2.3 New Semantics ........................................... 3
3. Terminology Mapping............................................ 4 3. Terminology Mapping............................................. 4
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................................ 7
5. SCSI Commands.................................................. 8 5. SCSI Commands................................................... 8
5.1 SCSI Command Additions ................................. 8 5.1 SCSI Command Additions .................................. 8
5.1.1 Command Priority (byte 2) .......................... 8 5.1.1 Command Priority (byte 2) ........................... 9
5.2 SCSI Response Additions ................................ 9 5.2 SCSI Response Additions ................................. 9
5.2.1 Status Qualifier .................................. 10 5.2.1 Status Qualifier ................................... 10
5.2.2 Data Segment - Sense and Response Data Segment .... 10 5.2.2 Data Segment - Sense and Response Data Segment ..... 10
6. Task Management Functions..................................... 10 6. Task Management Functions...................................... 11
6.1 Existing Task Management Functions .................... 10 6.1 Existing Task Management Functions ..................... 11
6.2 Task Management Function Additions .................... 10 6.2 Task Management Function Additions ..................... 12
6.2.1 LUN field ......................................... 12 6.2.1 LUN field .......................................... 14
6.2.2 Referenced Task Tag ............................... 12 6.2.2 Referenced Task Tag ................................ 14
6.2.3 RefCmdSN .......................................... 12 6.2.3 RefCmdSN ........................................... 14
6.3 Task Management Function Responses .................... 13 6.3 Task Management Function Responses ..................... 14
6.3.1 Task Management Function Response Additions ....... 14 6.3.1 Task Management Function Response Additions ........ 16
6.4 Task Management Requests Affecting Multiple Tasks ..... 14 6.4 Task Management Requests Affecting Multiple Tasks ...... 16
7. Login/Text Operational Text Keys.............................. 15 7. Login/Text Operational Text Keys............................... 17
7.1 New Operational Text Keys ............................. 15 7.1 New Operational Text Keys .............................. 17
7.1.1 iSCSIProtocolLevel ................................ 15 7.1.1 iSCSIProtocolLevel ................................. 17
8. Security Considerations....................................... 16 8. Security Considerations........................................ 18
9. IANA Considerations........................................... 16 9. IANA Considerations............................................ 18
10. References................................................... 18 10. References.................................................... 21
11. Acknowledgements............................................. 19 11. Acknowledgements.............................................. 22
1. Introduction 1. Introduction
The original iSCSI protocol [RFC3720] was built based on the The original iSCSI protocol [RFC3720] was built based on the
[SAM2] model for SCSI. Several new features and capabilities [SAM2] model for SCSI. Several new features and capabilities
have been added to the SCSI Architecture Model in the intervening have been added to the SCSI Architecture Model in the intervening
years (at the time of publication of this document, SAM-5 was the years (at the time of publication of this document, SAM-5 was the
current version of the SCSI Architecture Model). This document current version of the SCSI Architecture Model). This document
is not a complete revision of [RFC3720]. Instead, this document is not a complete revision of [RFC3720]. Instead, this document
is intended as a companion document to [draft-ietf-storm-iscsi- is intended as a companion document to [draft-ietf-storm-iscsi-
cons-xx]; this document may also be used as a companion document cons-xx]; this document may also be used as a companion document
to the combination of [RFC3720] and [RFC5048], although both of to the combination of [RFC3720] and [RFC5048], although both of
those RFCs have been obsolete by [draft-ietf-storm-iscsi-cons- those RFCs have been obsolete by [draft-ietf-storm-iscsi-cons-
xx]. xx].
-------------------------------------------------------- --------------------------------------------------------
RFC EDITORS NOTE: The above references to [draft-ietf-storm- RFC EDITORS NOTE: The above references to [draft-ietf-storm-
iscsi-cons-xx] should reference the RFC number assigned to iscsi-cons-xx] should reference the RFC number assigned to
that document, and this note should be removed. that document, and this note should be removed.
-------------------------------------------------------- --------------------------------------------------------
2. Definitions, Acronyms, and Document Summary 2. Definitions, Acronyms, and Document Summary
2.1 Definitions 2.1 Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
in this document are to be interpreted as described in in this document are to be interpreted as described in
[RFC2119]. [RFC2119].
2.2 Acronyms 2.2 Acronyms
ISID Initiator Session Identifier ISID Initiator Session Identifier
LU Logical Unit LU Logical Unit
PDU Protocol Data Unit PDU Protocol Data Unit
SAM-4 SCSI Architecture Model - 4 (see [SAM4]) SAM-4 SCSI Architecture Model - 4 (see [SAM4])
SAM-5 SCSI Architecture Model - 5 (see [SAM5]) SAM-5 SCSI Architecture Model - 5 (see [SAM5])
TMF Task Management Function TMF Task Management Function
2.3 New Semantics 2.3 New Semantics
This document specifies new iSCSI semantics. This section This document specifies new iSCSI semantics. This section
summarizes the contents of the document. summarizes the contents of the document.
Section 3: The mapping of iSCSI objects to SAM-5 objects Section 3: The mapping of iSCSI objects to SAM-5 objects
The iSCSI node may contain both initiator and The iSCSI node may contain both initiator and
target capabilities. target capabilities.
Section 4: The protocol used to negotiate the use of the new Section 4: The protocol used to negotiate the use of the new
capabilities described in this document. capabilities described in this document.
Section 5: New Command operations Section 5: New Command operations
The PRI field for SCSI command priority has been The PRI field for SCSI command priority has been
added to the SCSI command PDU (see 5.1.1). added to the SCSI command PDU (see 5.1.1).
The Status Qualifier field has been added to the The Status Qualifier field has been added to the
SCSI response PDU (see 5.2.1). SCSI response PDU (see 5.2.1).
Sense data may be returned (via autosense) for any Sense data may be returned (via autosense) for any
SCSI status, not just CHECK CONDITION (see 5.2.2). SCSI status, not just CHECK CONDITION (see 5.2.2).
Section 6: New Task Management Functions Section 6: New Task Management Functions
Four new task management functions (QUERY TASK, Four new task management functions (QUERY TASK,
QUERY TASK SET, I_T NEXUS RESET, and QUERY QUERY TASK SET, I_T NEXUS RESET, and QUERY
ASYNCHRONOUS EVENT have been added (see 6.2). ASYNCHRONOUS EVENT have been added (see 6.3).
A new "function succeeded" response has been added A new "function succeeded" response has been added
(see 6.3.1). (see 6.4.2).
Section 7: New Negotiation key Section 7: New Negotiation key
A new negotiation key has been added to enable the A new negotiation key has been added to enable the
use of the new features in section 5 and section 6. use of the new features in section 5 and section 6.
3. Terminology Mapping 3. Terminology Mapping
The iSCSI model (defined in [RFC3720]) uses different terminology The iSCSI model (defined in [RFC-cons]) uses different
than the SCSI Architecture Model. In some cases, iSCSI uses terminology than the SCSI Architecture Model. In some cases,
multiple terms to describe what in the SCSI Architecture Model is iSCSI uses multiple terms to describe what in the SCSI
described with a single term. The iSCSI terms and SAM-5 terms Architecture Model is described with a single term. The iSCSI
are not necessarily equivalent, but rather, the iSCSI terms terms and SAM-5 terms are not necessarily equivalent, but rather,
represent examples of the objects or classes described in SAM-5 the iSCSI terms represent examples of the objects or classes
as follows: described in SAM-5 as follows:
+-----------------------------+---------------------------+ --------------------------------------------------------
| RFCxxx Terminology | SAM-5 Terminology | RFC EDITORS NOTE: The above reference to [RFC-cons] should
+-----------------------------+---------------------------+ reference the RFC number assigned to [draft-ietf-storm-iscsi-
| Network Entity | none | cons-xx], and this note should be removed.
+-----------------------------+---------------------------+ --------------------------------------------------------
| 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 +-----------------------------+---------------------------+
Group Tag value includes an initial ,,0X or ,,0x (see [RFC3720]). | RFCxxx Terminology | SAM-5 Terminology |
+-----------------------------+---------------------------+
| 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
RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx] Group Tag value includes an initial ,,0X or ,,0x (see [RFC-
should reference this RFC, and this note should be removed. cons]).
--------------------------------------------------------
The following diagram shows an example of a combination target --------------------------------------------------------
device and initiator device. Such a configuration may exist in a RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx]
target device that implements a SCSI Copy Manager. This example should reference this RFC, and this note should be removed.
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--------------------- 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.
| +----------+ +----------+ | | +----------+ | --------------------------------------------------------
| | Network | | Network | | | | Network | |
| | Portal A | | Portal B | | | | Portal A | | The following diagram shows an example of a combination target
| +----------+ +----------+ | | +----------+ | device and initiator device. Such a configuration may exist in a
| | Target | | | | Initiator | target device that implements a SCSI Copy Manager. This example
| | Portal | | | | Portal | shows how a session that shares Network Portals within a Portal
| | Group 1 | | | | Group 2 | 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---------------------
| | |
+----|---------------|-------+ +----|------------+
| +----------+ +----------+ | | +----------+ |
| | 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)|| | | ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| |
| || || || || | | || || || || |
| || (TSIH = 56) || || (SSID = 48) || | | || (TSIH = 56) || || (SSID = 48) || |
| |+---------------------------+| |+------------------------------+| | | |+---------------------------+| |+------------------------------+| |
| | | | | | | | | | | |
| | iSCSI Target Node | | iSCSI Initiator Node | | | | iSCSI Target Node | | iSCSI Initiator Node | |
| +-----------------------------+ +--------------------------------+ | | +-----------------------------+ +--------------------------------+ |
| iSCSI Node | | iSCSI Node |
| (within Network Entity, not shown) | | (within Network Entity, not shown) |
+--------------------------------------------------------------------+ +--------------------------------------------------------------------+
4. New Feature Use 4. New Feature Use
4.1 Negotiation of New Feature Use 4.1 Negotiation of New Feature Use
The iSCSIProtocolLevel operational text key (see 7.1.1) The iSCSIProtocolLevel operational text key (see 7.1.1)
containing a value of "2" or higher MUST be negotiated to enable containing a value of "2" MUST be negotiated to enable the use of
the use of features described in this RFC. features described in this RFC.
Note that an operational value of "2" or higher for this key on The iSCSIProtocolLevel operational text key (see 7.1.1)
an iSCSI session does not influence the SCSI level features in containing a value of "2" MUST be negotiated to enable the use of
any way on that I_T nexus. An operational value of "2" or higher features described in this RFC. This is an iSCSI negotiation
for this key permits the iSCSI-related features defined in this mechanism that enabled iSCSI support for corresponding SCSI
document to be used on all connections on this iSCSI session. capabilities (see [SAM5] and [SPC4]. For this reason,
SCSI level hand-shakes (e.g. commands, mode pages) eventually negotiation of this key to a value of "2" is necessary, but not
determine the existence or lack of various SAM-5 features sufficient for hse of the SCSI capabilities enabled by the iSCSI
available for the I_T nexus between the two SCSI end points). To features in this RFC.
summarize, negotiation of this key to "2" or higher is a
necessary but not a sufficient condition of SAM-5 compliant
feature usage at the SCSI protocol level.
For example, an iSCSI implementation may negotiate this new key For example, an iSCSI implementation may negotiate this new key
to "2" but respond to the new task management functions (see 6.2) to "2" but respond to the new task management functions (see 6.3)
with a "Task management function not supported" (which indicates with a "Task management function not supported" (which indicates
a SCSI error that prevents the function from being performed). a SCSI error that prevents the function from being performed).
In contrast, if the key is negotiated to "2", an iSCSI In contrast, if the key is negotiated to "2", an iSCSI
implementation MUST NOT reject a task management function request implementation MUST NOT reject a task management function request
PDU that requests one of the new task management functions (such PDU that requests one of the new task management functions (as
a reject would report an iSCSI protocol error). such a reject would report an iSCSI protocol error).
4.2 Impact on standard INQUIRY data 4.2 Impact on standard INQUIRY data
The negotiated value of the iSCSIProtocolLevel key is an The negotiated value of the iSCSIProtocolLevel key is an
increment from the base iSCSI version descriptor value increment from the base iSCSI version descriptor value
(0960h)(see [SPC4]). If the SCSI device server returns an iSCSI (0960h)(see [SPC4]). If the SCSI device server returns an iSCSI
version descriptor in the standard INQUIRY data, then the value version descriptor in the standard INQUIRY data, then the value
returned in that iSCSI version descriptor MUST be set to the sum returned in that iSCSI version descriptor MUST be set to the sum
of the base value (0960h) plus the negotiated value of the of the base value (0960h) plus the negotiated value of the
iSCSIProtocolLevel key (for example, if the negotiated iSCSIProtocolLevel key (for example, if the negotiated
iSCSIProtocolLevel=2, then if an iSCSI version descriptor is iSCSIProtocolLevel=2, then if an iSCSI version descriptor is
returned in the standard INQUIRY data it is set to 0962h). returned in the standard INQUIRY data it is set to 0962h).
5. SCSI Commands 5. SCSI Commands
5.1 SCSI Command Additions 5.1 SCSI Command Additions
The format of the SCSI Command PDU is: The format of the SCSI Command PDU is:
Byte/ 0 | 1 | 2 | 3 | Byte/ 0 | 1 | 2 | 3 |
/ | | | | / | | | |
|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
reference to show the PRI field. For any field other than the
PRI field, the text in [RFC-cons] supersedes the text in section
5.1 of this document in the event the two documents conflict.
--------------------------------------------------------
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.
--------------------------------------------------------
5.1.1 Command Priority (byte 2)
The Command Priority (PRI) is a four (4) bit field that specifies
the relative scheduling importance of this task in relation to
other SIMPLE tasks already in the task set (see [SAM4]).
Section 11, iSCSI PDU Formats of [RFC-cons], 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".
--------------------------------------------------------
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 iSCSI targets unless the
iSCSIProtocolLevel text key with a value of "2" as defined in
section 7.1.1 was negotiated on the session.
See [SAM5] for special considerations on the use of the priority
field.
5.2 SCSI Response Additions
The format of the SCSI Response PDU is:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|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 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 | 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
reference to show the Status Qualifier field. For any 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.
--------------------------------------------------------
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 Status Qualifier provides additional status information (see
[SAM4]).
As defined in Section 11, iSCSI PDU Formats of [RFC-cons],
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.
--------------------------------------------------------
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
iSCSIProtocolLevel text key with a value of "2" as defined in
section 7.1.1 was negotiated on the session.
5.2.2 Data Segment - Sense and Response Data Segment
Section 11.4.7 of [RFC-cons] 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 [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.
--------------------------------------------------------
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
6.1 Task Management Function Request PDU
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|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 | 4|TotalAHSLength | DataSegmentLength |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
8| Logical Unit Number (LUN) | 8| Logical Unit Number (LUN) |
+ + + +
12| | 12| |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
16| Initiator Task Tag | 16| Initiator Task Tag |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
20| Expected Data Transfer Length | 20| Referenced Task Tag or 0xffffffff |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
24| CmdSN | 24| CmdSN |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
28| ExpStatSN | 28| ExpStatSN |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
32/ SCSI Command Descriptor Block (CDB) / 32| RefCmdSN or Reserved |
+/ /
+---------------+---------------+---------------+---------------+
48/ AHS (Optional) /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
x/ Header Digest (Optional) / 36| ExpDataSN or Reserved |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
y/ (DataSegment, Command Data) (Optional) / 40| Reserved /
+/ / +/ /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
z/ Data Digest (Optional) / 48| Header-Digest (Optional) |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
5.1.1 Command Priority (byte 2) The Task Management Function Request PDU above is duplicated from
[RFC-cons] for reference only. [RFC-cons] supersedes the text in
The Command Priority (PRI) specifies the relative scheduling
importance of this task in relation to other SIMPLE tasks already
in the task set (see [SAM4]).
Section 10, iSCSI PDU Formats of [RFC3720], requires that senders section 6.1 and 6.2 of this document in the event the two
set this field to zero. A sender MUST NOT set this field to a documents conflict.
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" or higher.
This field MUST be ignored by iSCSI targets unless the --------------------------------------------------------
iSCSIProtocolLevel text key with a value of "2" or higher as RFC EDITORS NOTE: The above references to [RFC-cons] should
defined in section 7.1.1 was negotiated on the session. reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
5.2 SCSI Response Additions 6.2 Existing Task Management Functions
The format of the SCSI Response PDU is: Section 11.5 of [RFC-cons] defines the semantics used to request
SCSI Task Management Functions be performed. The following task
management functions are defined:
Byte/ 0 | 1 | 2 | 3 | 1 - ABORT TASK
/ | | | | 2 - ABORT TASK SET
|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| 3 - CLEAR ACA
+---------------+---------------+---------------+---------------+ 4 - CLEAR TASK SET
0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status | 5 - LOGICAL UNIT RESET
+---------------+---------------+---------------+---------------+ 6 - TARGET WARM RESET
4|TotalAHSLength | DataSegmentLength | 7 - TARGET COLD RESET
+---------------+---------------+---------------+---------------+ 8 - TASK REASSIGN
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) |
+---------------+---------------+---------------+---------------+
5.2.1 Status Qualifier --------------------------------------------------------
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.
--------------------------------------------------------
The Status Qualifier provides additional status information (see 6.3 Task Management Function Additions
[SAM4]).
As defined in Section 10, iSCSI PDU Formats of [RFC3720], Additional task Management function codes are listed below. For
compliant senders already set this field to zero. Compliant a more detailed description of SCSI task management, see [SAM5].
senders MUST NOT set this field to a value other than zero unless
the iSCSIProtocolLevel text key with a value of "2" or higher as
defined in section 7.1.1 was negotiated on the session.
This field MUST be ignored by receivers unless the 9 - QUERY TASK - determines if the command identified by the
iSCSIProtocolLevel text key with a value of "2" or higher as Referenced Task Tag field is present in the task set.
defined in section 7.1.1 was negotiated on the session.
5.2.2 Data Segment - Sense and Response Data Segment 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.
Section 10.4.7 of [RFC3720] specifies that iSCSI targets MUST 11 - I_T NEXUS RESET - perform an I_T nexus loss function (see
support and enable autosense. If Status is CHECK CONDITION [SAM5]) for the I_T nexus on which the task management
(0x02), then the Data Segment MUST contain sense data for the function was received.
failed command. While [RFC3720] 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" or higher 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. Task Management Functions 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.
6.1 Existing Task Management Functions 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.
Section 10.5 of [RFC3720] defines the semantics used to request Any compliant initiator that sends any of the new task management
SCSI Task Management Functions be performed. The following task functions defined in this section MUST also support all new task
management functions are defined: management function responses (as specified in section 6.4.2).
1 - ABORT TASK For all of the task management functions detailed in this
2 - ABORT TASK SET section, the Task Management function response MUST be returned
3 - CLEAR ACA as detailed in section 6.4.
4 - CLEAR TASK SET
5 - LOGICAL UNIT RESET
6 - TARGET WARM RESET
7 - TARGET COLD RESET
8 - TASK REASSIGN
6.2 Task Management Function Additions 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 a
commands covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK
SET.
Additional task Management function codes are listed below. For If a QUERY TASK is issued for a task created by an immediate
a more detailed description of SCSI task management, see [SAM5]. command then RefCmdSN MUST be that of the Task Management request
itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN
MUST be set to the CmdSN of the task to be queried (lower than
CmdSN).
9 - QUERY TASK - determines if the command identified by the If the connection is still active (it is not undergoing an
Referenced Task Tag field is present in the task set. implicit or explicit logout), QUERY TASK MUST be issued on the
same connection to which the task to be queried is allegiant at
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.
10 - QUERY TASK SET - determine if any command is present in At the target a QUERY TASK function MUST NOT be executed on a
the task set for the I_T_L Nexus on which the task management Task Management request; such a request MUST result in Task
function was received. Management response of "Function rejected".
11 - I_T NEXUS RESET - perform an I_T nexus loss function (see For the I_T NEXUS RESET function, the target device MUST respond
[SAM5]) for the I_T nexus on which the task management to the function as defined in [SAM4]. Each logical unit
function was received. accessible via the receiving I_T NEXUS MUST behave as dictated by
the I_T nexus loss function in [SAM4] 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].
12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit --------------------------------------------------------
attention condition or a deferred error pending for the I_T_L RFC EDITORS NOTE: The above references to [RFC-cons] should
nexus on which the task management function was received. reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
These task management function requests MUST NOT be sent unless 6.3.1 LUN field
the iSCSIProtocolLevel text key with a value of "2" or higher as
defined in section 7.1.1 was negotiated on the session.
Any compliant initiator that sends any of the new task management This field is required for functions that address a specific LU
functions defined in this section MUST also support all new task (i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA,
management function responses (as specified in section 6.3.1). LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY
ASYNCHRONOUS EVENT) and is reserved in all others.
For all of the task management functions detailed in this 6.3.2 Referenced Task Tag
section, the Task Management function response MUST be returned
as detailed in section 6.3 Task Management Function Response.
The iSCSI target MUST ensure that no responses for the commands The Initiator Task Tag of the task to be aborted for the ABORT
covered by a task management function are sent to the iSCSI TASK function, reassigned for the TASK REASSIGN function, or
initiator port after the Task Management response except for a queried for the QUERY TASK function. For all other functions
commands covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK this field MUST be set to the reserved value 0xffffffff.
SET.
If a QUERY TASK is issued for a task created by an immediate 6.3.3 RefCmdSN
command then RefCmdSN MUST be that of the Task Management request
itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN
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 If a QUERY TASK is issued for a task created by an immediate
implicit or explicit logout), QUERY TASK MUST be issued on the command then RefCmdSN MUST be that of the Task Management request
same connection to which the task to be queried is allegiant at itself (i.e., CmdSN and RefCmdSN are equal).
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 For a QUERY TASK of a task created by non-immediate command
Task Management request; such a request MUST result in Task RefCmdSN MUST be set to the CmdSN of the task identified by the
Management response of "Function rejected". 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.
For the I_T NEXUS RESET function, the target device MUST respond --------------------------------------------------------
to the function as defined in [SAM4]. Each logical unit RFC EDITORS NOTE: The above references to [RFC-cons] should
accessible via the receiving I_T NEXUS MUST behave as dictated by reference the RFC number assigned to [draft-ietf-storm-iscsi-
the I_T nexus loss function in [SAM4] for the I_T nexus on which cons-xx], and this note should be removed.
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 [RFC3720], which in turn
triggers the I_T nexus loss notification to the SCSI layer as
described in [RFC3720].
6.2.1 LUN field 6.4 Task Management Function Responses
This field is required for functions that address a specific LU 6.4.1 Task Management Function Response PDU
(i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA,
LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY
ASYNCHRONOUS EVENT) and is reserved in all others.
6.2.2 Referenced Task Tag Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|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) |
+---------------+---------------+---------------+---------------+
The Initiator Task Tag of the task to be aborted for the ABORT Section 11.6 of [RFC-cons] defines the semantics used for
TASK function, reassigned for the TASK REASSIGN function, or responses to SCSI Task Management Functions. The following
queried for the QUERY TASK function. For all other functions responses are defined in [RFC-cons]:
this field MUST be set to the reserved value 0xffffffff.
6.2.3 RefCmdSN 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.
If a QUERY TASK is issued for a task created by an immediate The Task Management Function Response PDU above and the list of
command then RefCmdSN MUST be that of the Task Management request task management function responses above are duplicated from
itself (i.e., CmdSN and RefCmdSN are equal). [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.
For a QUERY TASK of a task created by non-immediate command --------------------------------------------------------
RefCmdSN MUST be set to the CmdSN of the task identified by the RFC EDITORS NOTE: The above references to [RFC-cons] should
Referenced Task Tag field. Targets must use this field as reference the RFC number assigned to [draft-ietf-storm-iscsi-
described in section 10.6.1 of [RFC3720] when the task identified cons-xx], and this note should be removed.
by the Referenced Task Tag field is not in the task set. --------------------------------------------------------
6.3 Task Management Function Responses Responses to new task management functions (see 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].
Byte/ 0 | 1 | 2 | 3 | For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET,
/ | | | | and QUERY ASYNCHRONOUS EVENT, the target performs the requested
|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| Task Management function and sends a Task Management response
+---------------+---------------+---------------+---------------+ back to the initiator.
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 10.6 of [RFC3720] defines the semantics used for 6.4.2 Task Management Function Response Additions
responses to SCSI Task Management Functions. The following
responses are defined in [RFC3720]:
0 - Function Complete. The new response is listed below:
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.
Responses to new task management functions (see 6.3.1) are listed 7 - Function succeeded.
below. In addition, a new task Management response is listed
below. For a more detailed description of SCSI task management
responses, see [SAM5].
For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, In symbolic terms Response value 7 maps to the SCSI service
and QUERY ASYNCHRONOUS EVENT, the target performs the requested response of FUNCTION SUCCEEDED in [SAM4].
Task Management function and sends a Task Management response
back to the initiator.
6.3.1 Task Management Function Response Additions The task management function response of "Function succeeded"
MUST be supported by an initiator that sends any of the new task
management functions (see 6.3).
The new response is listed below: 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.
7 - Function succeeded. For the QUERY TASK SET function, if there is any command present
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.
In symbolic terms Response value 7 maps to the SCSI service For the I_T NEXUS RESET function, after completion of the events
response of FUNCTION SUCCEEDED in [SAM4]. described in section 6.3 for this function, the logical unit
returns a Response value of Function complete. However, because
the target drops all connections, the Service Response (defined
by [SAM4]) for this SCSI task management function may not be
reliably delivered to the issuing initiator port.
The task management function response of "Function succeeded" For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention
MUST be supported by an initiator that sends any of the new task condition or deferred error pending for the specified I_T_L
management functions (see 6.2). nexus, then the logical unit returns a Response value of Function
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.
For the QUERY TASK function, if the specified task is in the task 6.5 Task Management Requests Affecting Multiple Tasks
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 Section 4.1 of [RFC5048] defines the notion of "affected tasks"
in the task set from the specified I_T_L nexus, then the logical in multi-task abort scenarios. This section adds to the list
unit returns a Response value of Function succeeded. If there include in that section by defining the tasks affected by the I_T
are no commands present in the task set from the specified I_T_L NEXUS RESET function.
nexus, then the logical unit returns a Response value of Function
complete.
For the I_T NEXUS RESET function, after completion of the events I_T NEXUS RESET: All outstanding tasks received on the I_T
described in section 6.2 for this function, the logical unit nexus on which the function request was received for all
returns a Response value of Function complete. However, because logical units accessible to the I_T nexus.
the target drops all connections, the Service Response (defined
by [SAM4]) 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 Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048]
condition or deferred error pending for the specified I_T_L identify semantics for task management functions that involve
nexus, then the logical unit returns a Response value of Function multi-task abort operations. If an iSCSI implementation supports
succeeded and additional response information is returned as the I_T NEXUS RESET function, it MUST also support the protocol
specified in [SAM5]. If there is no unit attention or deferred behavior as defined in those sections and follow the sequence of
error pending for the specified I_T_L nexus then the logical unit actions as described in those sections when processing the I_T
returns a Response value of Function complete. NEXUS RESET function.
6.4 Task Management Requests Affecting Multiple Tasks 7. Login/Text Operational Text Keys
Section 4.1 of [RFC5048] defines the notion of "affected tasks" 7.1 New Operational Text Keys
in multi-task abort scenarios. This section adds to the list
include in that section by defining the tasks affected by the I_T
NEXUS RESET function.
I_T NEXUS RESET: All outstanding tasks received on the I_T 7.1.1 iSCSIProtocolLevel
nexus on which the function request was received for all
logical units accessible to the I_T nexus.
Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048] Use: LO, IO
identify semantics for task management functions that involve Irrelevant when: SessionType = Discovery
multi-task abort operations. If an iSCSI implementation supports Senders: Initiator and Target
the I_T NEXUS RESET function, it MUST also support the protocol Scope: SW
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.
7. Login/Text Operational Text Keys iSCSIProtocolLevel=<numerical-value-from-0-to-31>
7.1 New Operational Text Keys Default is 1.
Result function is Minimum.
7.1.1 iSCSIProtocolLevel This key is used to negotiate the use of iSCSI features that
require different levels of protocol support (e.g., PDU formats,
end node semantics) for proper operation.
Use: LO, IO Negotiation of the iSCSIProtocolLevel key to a value
Irrelevant when: SessionType = Discovery corresponding to an RFC indicates that both negotiating parties
Senders: Initiator and Target are compliant to the RFC in question, and agree to support the
Scope: SW corresponding PDU formats and semantics on that iSCSI session.
An operational value of iSCSI ProtocolLevel = "x" on an iSCSI
session requires that the iSCSI protocol semantics on that iSCSI
session be a logical superset of the capabilities in all RFCs
that have claimed values of an iSCSIProtocolLevel less than "x".
iSCSIProtocolLevel=<numerical-value-from-0-to-31> An iSCSIProtocolLevel key negotiated to "0" indicates that the
implementation does not claim a specific iSCSI protocol level.
Default is 1. An iSCSIProtocolLevel key negotiated to "1" indicates that the
Result function is Minimum. implementation claims compliance with [RFC-cons].
This key is used to negotiate the use of iSCSI features that --------------------------------------------------------
require different levels of protocol support (e.g., PDU formats, RFC EDITORS NOTE: The above reference to [RFC-cons] should
end node semantics) for proper operation. reference the RFC number assigned to [draft-ietf-storm-iscsi-
cons-xx], and this note should be removed.
--------------------------------------------------------
Negotiation of the iSCSIProtocolLevel key to a value An iSCSIProtocolLevel key negotiated to "2" is required to enable
corresponding to an RFC indicates that both negotiating parties use of features defined in this RFC.
are compliant to the RFC in question, and agree to support the
corresponding PDU formats and semantics on that iSCSI session.
An operational value of iSCSI ProtocolLevel = "x" on an iSCSI
session requires that the iSCSI protocol semantics on that iSCSI
session be a logical superset of the capabilities in all RFCs
that have claimed values of an iSCSIProtocolLevel less than "x".
An iSCSIProtocolLevel key negotiated to "0" indicates that the If the negotiation answer is ignored by the acceptor, or the
implementation does not claim a specific iSCSI protocol level. answer 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.
An iSCSIProtocolLevel key negotiated to "2" or higher is required 8. Security Considerations
to enable use of features defined in this RFC.
If the negotiation answer is ignored by the acceptor, or the Poor implementations (those that do not observe the requirements
answer from the remote iSCSI end point is key=NotUnderstood, then described in [SAM5]) may allow the priority field (see 5.1.1) to
the features defined in this RFC, and the features defined in any be used to create a denial of service attack.
RFC requiring a key value greater than "2" MUST NOT be used.
8. Security Considerations All the iSCSI-related security text in [RFC3723] is also directly
applicable to this document.
At the time of writing this document does not introduce any new --------------------------------------------------------
security considerations other than those described in [RFC3720]. RFC EDITORS NOTE: The above reference to [RFC-cons] should
Consequently, all the iSCSI-related security text in [RFC3723] is reference the RFC number assigned to [draft-ietf-storm-iscsi-
also directly applicable to this document. cons-xx], and this note should be removed.
--------------------------------------------------------
9. IANA Considerations 9. IANA Considerations
This document modifies or creates a number of iSCSI-related This document modifies or creates a number of iSCSI-related
registries. The following iSCSI-related registries are modified: registries. The following iSCSI-related registries are modified:
1. iSCSI Task Management Functions Codes 1. iSCSI Task Management Functions Codes
Name of the existing registry: "iSCSI TMF Codes" Name of the existing registry: "iSCSI TMF Codes"
The name of this registry should be changed to: "iSCSI Task
Management Function Codes".
Additional entries: Additional entries:
9, QUERY TASK, [RFCxxx] 9, QUERY TASK, [RFCxxx]
10, QUERY TASK SET, [RFCxxx] 10, QUERY TASK SET, [RFCxxx]
11, I_T NEXUS RESET, [RFCxxx] 11, I_T NEXUS RESET, [RFCxxx]
12, QUERY ASYNCHRONOUS EVENT, [RFCxxx] 12, QUERY ASYNCHRONOUS EVENT, [RFCxxx]
--------------------------------------------------------- ---------------------------------------------------------
RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed.
---------------------------------------------------------
2. iSCSI Login/Text Keys RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed.
---------------------------------------------------------
Name of the existing registry: "iSCSI Text Keys" 2. iSCSI Login/Text Keys
Fields to record in the registry: Assigned value and its
associated RFC reference:
iSCSIProtocolLevel, [RFCxxx] Name of the existing registry: "iSCSI 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 iSCSIProtocolLevel, [RFCxxx]
IANA to manage.
3. iSCSI Protocol Level ---------------------------------------------------------
RFC EDITORS NOTE: The above references to [RFCxxx] should
reference this RFC, and this note should be removed.
---------------------------------------------------------
Name of new registry: "iSCSI Protocol Level" This document creates the following iSCSI-related registries for
IANA to manage.
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
INCITS T10 committee; therefore review by an expert that IESG-approved standards track specification defining the
maintains an association with that committee is required prior semantics and interoperability requirements of the proposed
to IESG approval of the associated specification. After new value and the 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).
1 and 3-31: range reserved by IANA for assignment in this Assignment policy:
registry.
Fields to record in the registry: Assigned value, and its The assignments of these values must be coordinated with the
associated RFC reference. 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).
0, [RFCxxx] Special care must be taken in the assignment of new values in
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.
2, [RFCxxx] 3-31: range reserved by IANA for assignment in this registry.
--------------------------------------------------------- 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.
---------------------------------------------------------
Allocation Policy: 0, [RFCxxx]
Expert review ([IANA]) and Standards Action ([IANA]) 1, [RFC-cons]
4. iSCSI Task Management Response Codes 2, [RFCxxx]
Name of new registry: "iSCSI TMF Response Codes" ---------------------------------------------------------
Namespace details: Numerical values that can fit in 8 bits. RFC EDITORS NOTE: The above references to [RFCxxx] should
reference this RFC, and this note should be removed. The
above references to [RFC-cons] should reference the [draft-
ietf-storm-iscsi-cons-xx] document, and this note should be
removed.
Information that must be provided to assign a new value: An ---------------------------------------------------------
IESG-approved specification defining the semantics and
interoperability requirements of the proposed new value and
the fields to be recorded in the registry.
Assignment policy: Allocation Policy:
If the requested value is not already assigned, it may be Expert review ([IANA]) and Standards Action ([IANA])
assigned to the requester.
8-254: Range reserved by iANA for assignment in this registry. 4. iSCSI Task Management Response Codes
Fields to record in the registry: Assigned value, Operation Name of new registry: "iSCSI Task Management Function Response
Name, and its associated RFC reference. Codes"
0x0, Function complete, [RFC3720] Namespace details: Numerical values that can fit in 8 bits.
0x1, Task does not exist, [RFC3720] Information that must be provided to assign a new value: An
IESG-approved specification defining the semantics and
interoperability requirements of the proposed new value and
the fields to be recorded in the registry.
0x2, LUN does not exist, [RFC3720] Assignment policy:
0x3, Task still allegiant, [RFC3720] If the requested value is not already assigned, it may be
assigned to the requester.
0x4, Task allegiance reassignment not supported, [RFC3720] 8-254: Range reserved by iANA for assignment in this registry.
0x5, Task management function not supported, [RFC3720] Fields to record in the registry: Assigned value, Operation
Name, and its associated RFC reference.
0x6, Function authorization failed, [RFC3720] 0x0, Function complete, [RFC-cons]
0x7, Function succeeded, [RFCxxx] 0x1, Task does not exist, [RFC-cons]
255, Function rejected, [RFC3720] 0x2, LUN does not exist, [RFC-cons]
0x3, Task still allegiant, [RFC-cons]
------------------------------------------------------------ 0x4, Task allegiance reassignment not supported, [RFC-cons]
RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed.
------------------------------------------------------------
Allocation Policy: 0x5, Task management function not supported, [RFC-cons]
Standards Action ([IANA]) 0x6, Function authorization failed, [RFC-cons]
10. References 0x7, Function succeeded, [RFCxxx]
10.1 Normative References 255, Function rejected, [RFC-cons]
[RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate ------------------------------------------------------------
Requirement Levels", BCP 14, RFC 2119, March 1997. RFC EDITORS NOTE: The above reference to [RFCxxx] should
reference this RFC, and this note should be removed.
[RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka, The above references to [RFC-cons] should reference the
M., and E. Zeidner, "Internet Small Computer Systems [draft-ietf-storm-iscsi-cons-xx] document, and this note
Interface (iSCSI)", RFC 3720, April 2004. should be removed.
------------------------------------------------------------
[RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and Allocation Policy:
Travostino, F., "Securing Block Storage Protocols
over IP", RFC 3723, April 2004.
[RFC5048] Chadalapaka, M., "Internet Small Computer System Standards Action ([IANA])
Interface (iSCSI) Corrections and Clarifications",
RFC 5048, October 2007.
[draft-ietf-storm-iscsi-cons-xx] Chadalapaka, M., Satran, J., 10. References
Kalman, M., "iSCSI Protocol (consolidated)", RFC xxx,
Date 2011.
------------------------------------------------------------ 10.1 Normative References
RFC EDITORS NOTE: The above references to [draft-ietf-storm-
iscsi-cons-xx] and [RFCxxx] should reference the RFC number
assigned to that draft, and this note should be removed.
------------------------------------------------------------
[IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing [RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate
an IANA Considerations Section in RFCs", BCP 26, RFC Requirement Levels", BCP 14, RFC 2119, March 1997.
5226, May 2008.
[SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2). [RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and
Travostino, F., "Securing Block Storage Protocols
over IP", RFC 3723, April 2004.
[SAM4] ISO/IEC 14776-414, SCSI Architecture Model - 4 (SAM- [RFC5048] Chadalapaka, M., "Internet Small Computer System
4). Interface (iSCSI) Corrections and Clarifications",
RFC 5048, October 2007.
[SAM5] T10/2104D rev r04, SCSI Architecture Model - 5 (SAM- [draft-ietf-storm-iscsi-cons-xx] Chadalapaka, M., Satran, J.,
5), Committee Draft. Kalman, M., "iSCSI Protocol (consolidated)", RFC xxx,
Date 2011.
[SPC4] T10/1731D rev r23, SCSI Primary Commands - 4 (SPC-4), ------------------------------------------------------------
Committee Draft. RFC EDITORS NOTE: The above references to [draft-ietf-storm-
iscsi-cons-xx] and [RFCxxx] should reference the RFC number
assigned to that draft, and this note should be removed.
------------------------------------------------------------
10.2 Additional Reference Sources [IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing
an IANA Considerations Section in RFCs", BCP 26, RFC
5226, May 2008.
For more information on the SCSI Architecture Model, contact the [SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2).
INCITS T10 Technical Committee for SCSI Storage Interfaces at
http://www.t10.org.
11. Acknowledgements [SAM4] ISO/IEC 14776-414, SCSI Architecture Model - 4 (SAM-
4).
The Storage Maintenance (STORM) Working Group in the Transport [SAM5] T10/2104D rev r04, SCSI Architecture Model - 5 (SAM-
Area of the IETF has been responsible for defining these 5), Committee Draft.
additions to the iSCSI protocol (apart from other relevant IP
Storage protocols). The editor acknowledges the contributions of
the entire working group.
The following individuals directly contributed to identifying
[RFCxxx] issues and/or suggesting resolutions to the issues
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 [SPC4] T10/1731D rev r36, SCSI Primary Commands - 4 (SPC-4),
Committee Draft.
Frederick Knight 10.2 Informative References
7301 Kit Creek Road
P.O. Box 13917
Research Triangle Park, NC 27709, USA
Phone: +1-919-476-5362
Email: knight@netapp.com
Mallikarjun Chadalapaka [RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka,
Microsoft M., and E. Zeidner, "Internet Small Computer Systems
One Microsoft Way Interface (iSCSI)", RFC 3720, April 2004.
Redmond, WA 98052 USA
Email: cbm@chadalapaka.com 10.3 Additional Reference Sources
For more information on the SCSI Architecture Model and SCSI
Primary Commands - 4, contact the INCITS T10 Technical Committee
for SCSI Storage Interfaces at http://www.t10.org.
11. Acknowledgements
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 editor acknowledges the contributions of
the entire working group.
The following individuals directly contributed to identifying
[RFCxxx] issues and/or suggesting resolutions to the issues
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
Frederick Knight
7301 Kit Creek Road
P.O. Box 13917
Research Triangle Park, NC 27709, USA
Phone: +1-919-476-5362
Email: knight@netapp.com
Mallikarjun Chadalapaka
Microsoft
One Microsoft Way
Redmond, WA 98052 USA
Email: cbm@chadalapaka.com
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