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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Storage Maintenance (StorM) Working Group Frederick Knight 2 Internet Draft NetApp 3 Intended status: Standards Track M. Chadalapaka 4 Expires: January 2012 Microsoft 5 Updates: 3720, 5048 July 2011 7 Internet Small Computer Systems Interface (iSCSI) SAM 8 draft-ietf-storm-iscsi-sam-03.txt 10 Abstract 12 Internet Small Computer Systems Interface (iSCSI) is a SCSI 13 transport protocol that maps the SCSI family of protocols onto 14 TCP/IP. RFC 3720 defines the iSCSI protocol. The current 15 iSCSI protocol (RFC 3720 and RFC 5048) is based on the SAM-2 16 version of the SCSI family of protocols). This document 17 defines additions and changes to the iSCSI protocol to enabled 18 additional features that were added to the SCSI family of 19 protocols through SAM-3, SAM-4, and SAM-5. 21 This document updates RFC 3720 and RFC 5048 and the text in 22 this document supersedes the text in RFC 3720 and RFC 5048 23 when the two differ. 25 Status of this Memo 27 This Internet-Draft is submitted to IETF in full conformance with 28 the provisions of BCP 78 and BCP 79. 30 Internet-Drafts are working documents of the Internet Engineering 31 Task Force (IETF), its areas, and its working groups. Note that 32 other groups may also distribute working documents as Internet- 33 Drafts. 35 Internet-Drafts are draft documents valid for a maximum of six 36 months and may be updated, replaced, or obsoleted by other 37 documents at any time. It is inappropriate to use Internet- 38 Drafts as reference material or to cite them other than as "work 39 in progress." 41 The list of current Internet-Drafts can be accessed at 42 http://www.ietf.org/1id-abstracts.html. 44 The list of Internet-Draft Shadow Directories can be accessed at 45 http://www.ietf.org/shadow.html. 47 This Internet-Draft will expire January, 2012. 49 Copyright Notice 51 Copyright (c) 2011 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with 59 respect to this document. Code Components extracted from this 60 document must include Simplified BSD License text as described in 61 Section 4.e of the Trust Legal Provisions and are provided 62 without warranty as described in the Simplified BSD License. 64 Table of Contents 66 1 Introduction.................................................. 3 67 2 Definitions, Acronyms, and Document Summary................... 3 68 2.1 Definitions ............................................ 3 69 2.2 Acronyms ............................................... 3 70 2.3 New Semantics .......................................... 3 71 3 Terminology Mapping........................................... 4 72 4 Negotiation of New Feature Use................................ 7 73 5 SCSI Commands................................................. 8 74 5.1 SCSI Command Additions ................................. 8 75 5.1.1 Command Priority (byte 2) .......................... 8 76 5.2 SCSI Response Additions ................................ 9 77 5.2.1 Status Qualifier .................................. 10 78 5.2.2 Data Segment - Sense and Response Data Segment .... 10 79 6 Task Management Functions.................................... 10 80 6.1 Existing Task Management Functions .................... 10 81 6.2 Task Management Function Additions .................... 10 82 6.2.1 LUN field ......................................... 12 83 6.2.2 Referenced Task Tag ............................... 12 84 6.2.3 RefCmdSN .......................................... 12 85 6.3 Task Management Function Responses .................... 13 86 6.3.1 Task Management Function Response Additions ....... 14 87 6.4 Task Management Requests Affecting Multiple Tasks ..... 14 88 7 Login/Text Operational Text Keys............................. 15 89 7.1 New Operational Text Keys ............................. 15 90 7.1.1 iSCSIProtocolLevel ................................ 15 91 8 Security Considerations...................................... 15 92 9 IANA Considerations.......................................... 16 93 10 References.................................................... 18 94 11 Acknowledgements.............................................. 19 95 1. Introduction 97 The original [RFC3720] was built based on the [SAM2] model for 98 SCSI. Several new features and capabilities have been added to 99 the SCSI Architecture Model in the intervening years (SAM5 is now 100 the current version of the SCSI Architecture Model). This 101 document is not a complete revision of [RFC3720]. Instead, this 102 document is intended as a companion document to [RFC3720] and 103 [RFC5048]. 105 The text in this document, however, updates and supersedes the 106 text in [RFC3720] and [RFC5048] whenever there is any conflict. 108 2. Definitions, Acronyms, and Document Summary 110 2.1 Definitions 112 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 113 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 114 this document are to be interpreted as described in [RFC2119]. 116 2.2 Acronyms 118 SAM4 SCSI Architecture Model - 4 119 SAM5 SCSI Architecture Model - 5 120 SAM SAM4 or SAM5 122 2.3 New Semantics 124 This document specifies new iSCSI semantics. This section 125 summarizes the contents of the document. 127 Section 3: The mapping of iSCSI objects to SAM5 objects 128 The iSCSI node may contain both initiator and 129 target capabilities. 131 Section 4: The protocol used to negotiate the use of the new 132 capabilities described in this document. 134 Section 5: New Command operations 135 The PRI field for SCSI command priority has been 136 added to the SCSI command PDU (see 5.1.1). 137 The Status Qualifier field has been added to the 138 SCSI response PDU (see 5.2.1). 139 Sense data may be returned (via autosense) for any 140 SCSI status, not just CHECK CONDITION (see 5.2.2). 142 Section 6: New Task Management Functions 143 Four new task management functions (QUERY TASK, 144 QUERY TASK SET, I_T NEXUS RESET, and QUERY 145 ASYNCHRONOUS EVENT have been added (see 6.2). 147 A new "function succeeded" response has been added 148 (see 6.3.1). 150 Section 7: New Negotiation key 151 A new negotiation key has been added to enable the 152 use of the new features in section 5 and section 6. 154 3. Terminology Mapping 156 The iSCSI model (defined in [RFC3720]) uses different terminology 157 than the SCSI Architecture Model. In some cases, iSCSI uses 158 multiple terms to describe what in the SCSI Architecture Model is 159 described with a single term. The iSCSI terms and SAM terms are 160 not necessarily equivalent, but rather, the iSCSI terms represent 161 examples of the objects or classes described in SAM as follows: 163 +-----------------------------+---------------------------+ 164 | RFCxxx Terminology | SAM Terminology | 165 +-----------------------------+---------------------------+ 166 | Network Entity | none | 167 +-----------------------------+---------------------------+ 168 | iSCSI Node | SCSI Device | 169 +-----------------------------+---------------------------+ 170 | iSCSI Name | SCSI Device Name | 171 +-----------------------------+---------------------------+ 172 | iSCSI Node Name | SCSI Device Name | 173 +-----------------------------+---------------------------+ 174 | iSCSI Initiator Node | SCSI Initiator Device | 175 +-----------------------------+---------------------------+ 176 | iSCSI Initiator Name | SCSI Device Name | 177 +-----------------------------+---------------------------+ 178 | iSCSI Initiator Port Name | SCSI Initiator Port Name | 179 | iSCSI Node Name + ',i,' + | | 180 | ISID | | 181 +-----------------------------+---------------------------+ 182 | iSCSI Target Node | SCSI Target Device | 183 +-----------------------------+---------------------------+ 184 | iSCSI Target Name | SCSI Device Name | 185 +-----------------------------+---------------------------+ 186 | iSCSI Target Port Name | SCSI Target Port Name | 187 | iSCSI Node Name + ',t,' + | | 188 | Target Portal Group Tag | | 189 +-----------------------------+---------------------------+ 190 | iSCSI Target Portal Group | SCSI Target Port | 191 +-----------------------------+---------------------------+ 192 | iSCSI Initiator Node + | SCSI Initiator Port | 193 | active ISID | | 194 +-----------------------------+---------------------------+ 195 | iSCSI Initiator Name + | I_T Nexus | 196 | ',i,' + ISID, iSCSI Target | | 197 | Name + ',t,' + Portal | | 198 | Group Tag | | 199 +-----------------------------+---------------------------+ 200 | Target Portal Group Tag | Relative Port ID | 201 +-----------------------------+---------------------------+ 203 -------------------------------------------------------- 204 RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx] 205 should reference this RFC, and this note should be removed. 206 -------------------------------------------------------- 208 The following diagram shows an example of a combination target 209 device and initiator device. Such a configuration may exist in a 210 target device that implements a SCSI Copy Manager. This example 211 shows how a session that shares Network Portals within a Portal 212 Group may be established (see Target Portal Group 1). In 213 addition, this example shows the Initiator using a different 214 Portal Group than the Target Portal Group, but the Initiator 215 Portal group sharing Network Portal A with the Target Portal 216 Group. 218 ----------------------------IP Network--------------------- 219 | | | 220 +----|---------------|-------+ +----|------------+ 221 | +----------+ +----------+ | | +----------+ | 222 | | Network | | Network | | | | Network | | 223 | | Portal A | | Portal B | | | | Portal A | | 224 | +----------+ +----------+ | | +----------+ | 225 | | Target | | | | Initiator | 226 | | Portal | | | | Portal | 227 | | Group 1 | | | | Group 2 | 228 +----|---------------|-------+ +----|------------+ 229 | | | 230 +----------|---------------|--------------------|--------------------+ 231 | +--------|---------------|----+ +-------------|------------------+ | 232 | |+-------|---------------|---+| |+------------|-----------------+| | 233 | ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| | 234 | || || || || | 235 | || (TSIH = 56) || || (SSID = 48) || | 236 | |+---------------------------+| |+------------------------------+| | 237 | | | | | | 238 | | iSCSI Target Node | | iSCSI Initiator Node | | 239 | +-----------------------------+ +--------------------------------+ | 240 | iSCSI Node | 241 | (within Network Entity, not shown) | 242 +--------------------------------------------------------------------+ 243 4. Negotiation of New Feature Use 245 The iSCSIProtocolLevel operational text key (see 7.1.1) 246 containing a value of "2" or higher MUST be negotiated to enable 247 the use of features described in this RFC. 249 Note that an operational value of "2" or higher for this key on 250 an iSCSI session does not influence the SCSI level features in 251 any way on that I_T nexus. An operational value of "2" or higher 252 for this key permits the iSCSI-related features defined in this 253 document to be used on all connections on this iSCSI session. 254 SCSI level hand-shakes (e.g. commands, mode pages) eventually 255 determine the existence or lack of various SAM features available 256 for the I_T nexus between the two SCSI end points). To 257 summarize, negotiation of this key to "2" or higher is a 258 necessary but not a sufficient condition of [SAM4] compliant 259 feature usage at the SCSI protocol level. 261 For example, an iSCSI implementation may negotiate this new key 262 to "2" but respond to the new task management functions (see 6.2) 263 with a "Task management function not supported" (which indicates 264 a SCSI error that prevents the function from being performed). 265 In contrast, if the key is negotiated to "2", an iSCSI 266 implementation MUST NOT reject a task management function request 267 PDU that requests one of the new task management functions (such 268 a reject would report an iSCSI protocol error). 270 5. SCSI Commands 272 5.1 SCSI Command Additions 274 The format of the SCSI Command PDU is: 276 Byte/ 0 | 1 | 2 | 3 | 277 / | | | | 278 |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| 279 +---------------+---------------+---------------+---------------+ 280 0|.|I| 0x01 |F|R|W|. .|ATTR | PRI | Reserved | 281 +---------------+---------------+---------------+---------------+ 282 4|TotalAHSLength | DataSegmentLength | 283 +---------------+---------------+---------------+---------------+ 284 8| Logical Unit Number (LUN) | 285 + + 286 12| | 287 +---------------+---------------+---------------+---------------+ 288 16| Initiator Task Tag | 289 +---------------+---------------+---------------+---------------+ 290 20| Expected Data Transfer Length | 291 +---------------+---------------+---------------+---------------+ 292 24| CmdSN | 293 +---------------+---------------+---------------+---------------+ 294 28| ExpStatSN | 295 +---------------+---------------+---------------+---------------+ 296 32/ SCSI Command Descriptor Block (CDB) / 297 +/ / 298 +---------------+---------------+---------------+---------------+ 299 48/ AHS (Optional) / 300 +---------------+---------------+---------------+---------------+ 301 x/ Header Digest (Optional) / 302 +---------------+---------------+---------------+---------------+ 303 y/ (DataSegment, Command Data) (Optional) / 304 +/ / 305 +---------------+---------------+---------------+---------------+ 306 z/ Data Digest (Optional) / 307 +---------------+---------------+---------------+---------------+ 309 5.1.1 Command Priority (byte 2) 311 The Command Priority (PRI) specifies the relative scheduling 312 importance of this task in relation to other SIMPLE tasks already 313 in the task set (see [SAM4]). 315 Section 10, iSCSI PDU Formats of [RFC3720], requires that senders 316 set this field to zero. A sender MUST NOT set this field to a 317 value other than zero unless the iSCSIProtocolLevel text key 318 defined in section 7.1.1 has been negotiated on the session with 319 a value of "2" or higher. 321 This field MUST be ignored by iSCSI targets unless the 322 iSCSIProtocolLevel text key with a value of "2" or higher as 323 defined in section 7.1.1 was negotiated on the session. 325 5.2 SCSI Response Additions 327 The format of the SCSI Response PDU is: 329 Byte/ 0 | 1 | 2 | 3 | 330 / | | | | 331 |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| 332 +---------------+---------------+---------------+---------------+ 333 0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status | 334 +---------------+---------------+---------------+---------------+ 335 4|TotalAHSLength | DataSegmentLength | 336 +---------------+---------------+---------------+---------------+ 337 8| Status Qualifier | Reserved | 338 +---------------+---------------+---------------+---------------+ 339 12| Reserved | 340 +---------------+---------------+---------------+---------------+ 341 16| Initiator Task Tag | 342 +---------------+---------------+---------------+---------------+ 343 20| SNACK Tag or Reserved | 344 +---------------+---------------+---------------+---------------+ 345 24| StatSN | 346 +---------------+---------------+---------------+---------------+ 347 28| ExpCmdSN | 348 +---------------+---------------+---------------+---------------+ 349 32| MaxCmdSN | 350 +---------------+---------------+---------------+---------------+ 351 36| ExpDataSN or Reserved | 352 +---------------+---------------+---------------+---------------+ 353 40| Bidirectional Read Residual Count or Reserved | 354 +---------------+---------------+---------------+---------------+ 355 44| Residual Count or Reserved | 356 +---------------+---------------+---------------+---------------+ 357 48| Header-Digest (Optional) | 358 +---------------+---------------+---------------+---------------+ 359 / Data Segment (Optional) / 360 +/ / 361 +---------------+---------------+---------------+---------------+ 362 | Data-Digest (Optional) | 363 +---------------+---------------+---------------+---------------+ 365 5.2.1 Status Qualifier 367 The Status Qualifier provides additional status information (see 368 [SAM4]). 370 As defined in Section 10, iSCSI PDU Formats of [RFC3720], 371 compliant senders already set this field to zero. Compliant 372 senders MUST NOT set this field to a value other than zero unless 373 the iSCSIProtocolLevel text key with a value of "2" or higher as 374 defined in section 7.1.1 was negotiated on the session. 376 This field MUST be ignored by receivers unless the 377 iSCSIProtocolLevel text key with a value of "2" or higher as 378 defined in section 7.1.1 was negotiated on the session. 380 5.2.2 Data Segment - Sense and Response Data Segment 382 Section 10.4.7 of [RFC3720] specifies that iSCSI targets MUST 383 support and enable autosense. If Status is CHECK CONDITION 384 (0x02), then the Data Segment MUST contain sense data for the 385 failed command. While [RFC3720] does not make any statements 386 about the state of the Data Segment when the Status is not CHECK 387 CONDITION (0x02)(i.e., the Data Segment is not prohibited from 388 containing sense data when the Status is not CHECK CONDITION), 389 negotiation of the iSCSIProtocolLevel text key with a value of 390 "2" or higher as defined in section 7.1.1 explicitly indicates 391 that the Data Segment MAY contain sense data at any time, no 392 matter what value is set in the Status field. 394 6. Task Management Functions 396 6.1 Existing Task Management Functions 398 Section 10.5 of [RFC3720] defines the semantics used to request 399 SCSI Task Management Functions be performed. The following task 400 management functions are defined: 402 1 - ABORT TASK 403 2 - ABORT TASK SET 404 3 - CLEAR ACA 405 4 - CLEAR TASK SET 406 5 - LOGICAL UNIT RESET 407 6 - TARGET WARM RESET 408 7 - TARGET COLD RESET 409 8 - TASK REASSIGN 411 6.2 Task Management Function Additions 413 Additional task Management function codes are listed below. For 414 a more detailed description of SCSI task management, see [SAM5]. 416 9 - QUERY TASK - determines if the task identified by the 417 Referenced Task Tag field is present in the task set. 419 10 - QUERY TASK SET - determine if any task is present in the 420 task set. 422 11 - I_T NEXUS RESET - perform an I_T nexus loss function for 423 the I_T nexus of each logical unit accessible through the I_T 424 Nexus on which the task management function was received. 426 12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit 427 attention condition or a deferred error pending for the I_T_L 428 nexus on which the task management function was received. 430 These task management function requests MUST NOT be sent unless 431 the iSCSIProtocolLevel text key with a value of "2" or higher as 432 defined in section 7.1.1 was negotiated on the session. 434 Any compliant initiator that sends any of the new task management 435 functions defined in this section MUST also support all new task 436 management function responses (see 6.3.1). 438 For all of the task management functions detailed in this 439 section, the Task Management function response MUST be returned 440 as detailed in section 6.3 Task Management Function Response. 442 The iSCSI target MUST ensure that no responses for the tasks 443 covered by a task management function are sent to the iSCSI 444 initiator after the Task Management response except for a task 445 covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK SET. 447 If a QUERY TASK is issued for a task created by an immediate 448 command then RefCmdSN MUST be that of the Task Management request 449 itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN 450 MUST be set to the CmdSN of the task to be queried (lower than 451 CmdSN). 453 At the target a QUERY TASK function MUST NOT be executed on a 454 Task Management request; such a request MUST result in Task 455 Management response of "Function rejected". 457 For the I_T NEXUS RESET function, the target device MUST respond 458 to the function as defined in [SAM4]. Each logical unit 459 accessible via the receiving I_T NEXUS MUST behave as dictated by 460 the I_T nexus loss function in [SAM4] for the I_T nexus on which 461 the task management function was received. The target device 462 MUST drop all connections in the session over which this function 463 is recevied. Independent of the DefaultTime2Wait and 464 DefaultTime2Retain value applicable to the session over which 465 this function is received, the target device MUST consider each 466 participating connection in the session to have immediately timed 467 out, leading to FREE state. The resulting timeouts cause the 468 session timeout event defined in [RFC3720], which in turn 469 triggers the I_T nexus loss notification to the SCSI layer as 470 described in [RFC3720]. 472 6.2.1 LUN field 474 This field is required for functions that address a specific LU 475 (i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA, 476 LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY 477 ASYNCHRONOUS EVENT) and is reserved in all others. 479 6.2.2 Referenced Task Tag 481 The Initiator Task Tag of the task to be aborted for the ABORT 482 TASK function, reassigned for the TASK REASSIGN function, or 483 queried for the QUERY TASK function. For all other functions 484 this field MUST be set to the reserved value 0xffffffff. 486 6.2.3 RefCmdSN 488 If a QUERY TASK is issued for a task created by an immediate 489 command then RefCmdSN MUST be that of the Task Management request 490 itself (i.e., CmdSN and RefCmdSN are equal). 492 For a QUERY TASK of a task created by non-immediate command 493 RefCmdSN MUST be set to the CmdSN of the task identified by the 494 Referenced Task Tag field. Targets must use this field as 495 described in section 10.6.1 of [RFC3720] when the task identified 496 by the Referenced Task Tag field is not in the task set. 498 6.3 Task Management Function Responses 500 Byte/ 0 | 1 | 2 | 3 | 501 / | | | | 502 |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| 503 +---------------+---------------+---------------+---------------+ 504 0|.|.| 0x22 |1| Reserved | Response | Reserved | 505 +---------------+---------------+---------------+---------------+ 506 4|TotalAHSLength | DataSegmentLength | 507 +-----------------------------------------------+---------------+ 508 8| Additional Response Information | Reserved | 509 +-----------------------------------------------+---------------+ 510 12| Reserved | 511 +---------------+---------------+---------------+---------------+ 512 16| Initiator Task Tag | 513 +---------------+---------------+---------------+---------------+ 514 20| Reserved | 515 +---------------+---------------+---------------+---------------+ 516 24| StatSN | 517 +---------------+---------------+---------------+---------------+ 518 28| ExpCmdSN | 519 +---------------+---------------+---------------+---------------+ 520 32| MaxCmdSN | 521 +---------------+---------------+---------------+---------------+ 522 36/ Reserved / 523 +/ / 524 +---------------+---------------+---------------+---------------+ 525 48| Header-Digest (Optional) | 526 +---------------+---------------+---------------+---------------+ 528 Section 10.6 of [RFC3720] defines the semantics used for 529 responses to SCSI Task Management Functions. The following 530 responses are defined in [RFC3720]: 532 0 - Function Complete. 533 1 - Task does not exist. 534 2 - LUN does not exist. 535 3 - Task still allegiant. 536 4 - Task allegiance reassignment not supported. 537 5 - Task management function not supported. 538 6 - Function authorization failed. 539 255 - Function rejected. 541 Responses to new task management functions (see 6.3.1) are listed 542 below. In addition, a new task Management response is listed 543 below. For a more detailed description of SCSI task management 544 responses, see [SAM5]. 546 For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, 547 and QUERY ASYNCHRONOUS EVENT, the target performs the requested 548 Task Management function and sends a Task Management response 549 back to the initiator. 551 6.3.1 Task Management Function Response Additions 553 The new response is listed below: 555 7 - Function succeeded. 557 In symbolic terms Response value 7 maps to the SCSI service 558 response of FUNCTION SUCCEEDED. 560 The task management function response of function succeeded MUST 561 be supported by an initiator that sends any of the new task 562 management functions (see 6.2). 564 For the QUERY TASK function, if the specified task is in the task 565 set, then the target returns a Response value of Function 566 succeeded and additional response information is returned as 567 specified in [SAM5]. If the specified task is not in the task 568 set, then the target returns a Response value of Function 569 complete. 571 For the QUERY TASK SET function, if there is any command present 572 in the task set from the specified I_T_L nexus, then the target 573 returns a Response value of Function succeeded. If there are no 574 commands present in the task set from the specified I_T_L nexus, 575 then the target returns a Response value of Function complete. 577 For the I_T NEXUS RESET function, after completion of the events 578 described in section 6.2 for this function, the target returns a 579 Response value of Function complete. However, because the target 580 drops all connections, the Service Response (defined by [SAM4]) 581 for this SCSI task management function may not be reliably 582 delivered to the issuing initiator port. 584 For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention 585 condition or deferred error pending for the specified I_T_L 586 nexus, then the target returns a Response value of Function 587 succeeded and additional response information is returned as 588 specified in [SAM5]. If there is no unit attention or deferred 589 error pending for the specified I_T_L nexus then the target 590 returns a Response value of Function complete. 592 6.4 Task Management Requests Affecting Multiple Tasks 594 Section 4.1 of [RFC5048] defines the notion of "affected tasks" 595 in multi-task abort scenarios. This section adds to the list 596 include in that section by defining the tasks affected by the I_T 597 NEXUS RESET function. 599 I_T NEXUS RESET: All outstanding tasks received on the I_T 600 nexus on which the function request was received for all 601 logical units accessible to the I_T nexus. 603 Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048] 604 identify semantics for task management functions that involve 605 multi-task abort operations. If an iSCSI implementation supports 606 the I_T NEXUS RESET function, it MUST also support the protocol 607 behavior as defined in those sections and follow the sequence of 608 actions as described in those sections when processing the I_T 609 NEXUS RESET function. 611 7. Login/Text Operational Text Keys 613 7.1 New Operational Text Keys 615 7.1.1 iSCSIProtocolLevel 617 Use: LO 618 Irrelevant when: SessionType = Discovery 619 Senders: Initiator and Target 620 Scope: SW 622 iSCSIProtocolLevel= 624 Default is 1. 625 Result function is Minimum. 627 This key is used to negotiate the use of iSCSI features that 628 require different levels of protocol support for proper 629 operation. This key is negotiated on the iSCSI session once the 630 session is in full feature phase. 632 Negotiation of the iSCSIProtocolLevel key to a value claimed by 633 an RFC indicates that both negotiating parties are compliant to 634 the RFC in question, and agree to support the corresponding 635 semantics on that iSCSI session. An operational value of iSCSI 636 ProtocolLevel = "x" on an iSCSI session requires that the iSCSI 637 protocol semantics on that iSCSI session be a logical superset of 638 the capabilities in all RFCs that have claimed values of an 639 iSCSIProtocolLevel less than "x". 641 An iSCSIProtocolLevel key negotiated to "2" or higher is required 642 to enable use of features defined in this RFC. 644 An iSCSIProtocolLevel key negotiated to "0" indicates that the 645 implementation does not claim a specific iSCSI protocol level. 647 If the negotiation answer is ignored by the acceptor, or the 648 answer from the remote iSCSI end point is key=NotUnderstood, then 649 the features defined in this RFC, and the features defined in any 650 RFC requiring a key value greater than "2" MUST NOT be used. 652 8. Security Considerations 653 At the time of writing this document does not introduce any new 654 security considerations other than those described in [RFC3720]. 655 Consequently, all the iSCSI-related security text in [RFC3723] is 656 also directly applicable to this document. 658 9. IANA Considerations 660 This document modifies or creates a number of iSCSI-related 661 registries. The following iSCSI-related registries are modified: 663 1. iSCSI Task Management Functions Codes 665 Name of the existing registry: "iSCSI TMF Codes" 667 Additional entries: 669 9, QUERY TASK, [RFCxxx] 671 10, QUERY TASK SET, [RFCxxx] 673 11, I_T NEXUS RESET, [RFCxxx] 675 12, QUERY ASYNCHRONOUS EVENT, [RFCxxx] 677 --------------------------------------------------------- 678 RFC EDITORS NOTE: The above reference to [RFCxxx] should 679 reference this RFC, and this note should be removed. 680 --------------------------------------------------------- 682 2. iSCSI Login/Text Keys 684 Name of the existing registry: "iSCSI Text Keys" 686 Fields to record in the registry: Assigned value and its 687 associated RFC reference: 689 iSCSIProtocolLevel, [RFCxxx] 691 --------------------------------------------------------- 692 RFC EDITORS NOTE: The above references to [RFCxxx] should 693 reference this RFC, and this note should be removed. 694 --------------------------------------------------------- 696 This document creates the following iSCSI-related registries for 697 IANA to manage. 699 3. iSCSI Protocol Level 701 Name of new registry: "iSCSI Protocol Level" 703 Namespace details: Numerical values from 0 to 65535 705 Information that must be provided to assign a new value: An 706 IESG-approved specification defining the semantics and 707 interoperability requirements of the proposed new value and 708 the fields to be recorded in the registry. 710 Assignment policy: 712 If the requested value is not already assigned, it may be 713 assigned to the requester. 715 1 and 3-65535: range reserved by IANA for assignment in this 716 registry. 718 Fields to record in the registry: Assigned value, and its 719 associated RFC reference. 721 0, [RFCxxx] 723 2, [RFCxxx] 725 --------------------------------------------------------- 726 RFC EDITORS NOTE: The above references to [RFCxxx] should 727 reference this RFC, and this note should be removed. 728 --------------------------------------------------------- 730 Allocation Policy: 732 Standards Action ([IANA]) 734 4. iSCSI Task Management Response Codes 736 Name of new registry: "iSCSI TMF Response Codes" 738 Namespace details: Numerical values that can fit in 8 bits. 740 Information that must be provided to assign a new value: An 741 IESG-approved specification defining the semantics and 742 interoperability requirements of the proposed new value and 743 the fields to be recorded in the registry. 745 Assignment policy: 747 If the requested value is not already assigned, it may be 748 assigned to the requester. 750 8-254: Range reserved by iANA for assignment in this registry. 752 Fields to record in the registry: Assigned value, Operation 753 Name, and its associated RFC reference. 755 0x0, Function complete, [RFC3720] 756 0x1, Task does not exist, [RFC3720] 758 0x2, LUN does not exist, [RFC3720] 760 0x3, Task still allegiant, [RFC3720] 762 0x4, Task allegiance reassignment not supported, [RFC3720] 764 0x5, Task management function not supported, [RFC3720] 766 0x6, Function authorization failed, [RFC3720] 768 0x7, Function succeeded, [RFCxxx] 770 255, Function rejected, [RFC3720] 772 ------------------------------------------------------------ 773 RFC EDITORS NOTE: The above reference to [RFCxxx] should 774 reference this RFC, and this note should be removed. 775 ------------------------------------------------------------ 777 Allocation Policy: 779 Standards Action ([IANA]) 781 10. References 783 10.1 Normative References 785 [RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate 786 Requirement Levels", BCP 14, RFC 2119, March 1997. 788 [RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka, 789 M., and E. Zeidner, "Internet Small Computer Systems 790 Interface (iSCSI)", RFC 3720, April 2004. 792 [RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and 793 Travostino, F., "Securing Block Storage Protocols 794 over IP", RFC 3723, April 2004. 796 [RFC5048] Chadalapaka, M., "Internet Small Computer System 797 Interface (iSCSI) Corrections and Clarifications", 798 RFC 5048, October 2007. 800 [IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing 801 an IANA Considerations Section in RFCs", BCP 26, RFC 802 5226,May 2008. 804 [SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2). 806 [SAM4] ISO/IEC 14776-414, SCSI Architecture Model - 4 (SAM- 807 4). 809 [SAM5] T10/2104D rev r05, SCSI Architecture Model - 5 (SAM- 810 5), Committee Draft. 812 10.2 Additional Reference Sources 814 For more information on the SCSI Architecture Model, contact the 815 T10 group at http://www.t10.org. 817 11. Acknowledgements 819 The Storage Maintenance (STORM) Working Group in the Transport 820 Area of the IETF has been responsible for defining these 821 additions to the iSCSI protocol (apart from other relevant IP 822 Storage protocols). The editor acknowledges the contributions of 823 the entire working group. 825 The following individuals directly contributed to identifying 826 [RFCxxx] issues and/or suggesting resolutions to the issues 827 clarified in this document: David Black, Rob Elliott. This 828 document benefited from all of these contributions. 830 ------------------------------------------------------------ 831 RFC EDITORS NOTE: The above reference to [RFCxxx] should 832 reference this RFC, and this note should be removed. 833 ------------------------------------------------------------ 835 Author's Addresses 837 Frederick Knight 838 7301 Kit Creek Road 839 P.O. Box 13917 840 Research Triangle Park, NC 27709, USA 841 Phone: +1-919-476-5362 842 Email: knight@netapp.com 844 Mallikarjun Chadalapaka 845 Microsoft 846 One Microsoft Way 847 Redmond, WA 98052 USA 848 EMail: cbm@chadalapaka.com