ANSI INCITS382-2004 Information Technology - SCSI Medium Changer Commands -2 (SMC-2)《信息技术.SCSI媒体变换器命令.2(SMC-2)》.pdf

1、American National StandardDeveloped byfor Information Technology SCSI Media Changer Commands-2(SMC-2)ANSI INCITS 382-2004ANSIINCITS382-2004Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from

2、 IHS-,-,-Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSIINCITS 382-2004American National Standardfor Information Technology SCSI Media Changer Commands-2(SMC-2)SecretariatIn

3、formation Technology Industry CouncilApproved October 5, 2004 American National Standards Institute, Inc.AbstractThis standard defines the SCSI commands and model for independent media changer devices and at-tached media changer functions integrated into other SCSI devices.Copyright American Nationa

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10、ng the AmericanNational Standards Institute.American National StandardPublished byAmerican National Standards Institute, Inc.25 West 43rd Street, New York, NY 10036Copyright 2004 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyf

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14、e use of this standard.Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iContentsPageForeword vIntroduction vii1 Scope. 12 Normative references. 53 Definitions, symbols and abbrev

15、iations 53.1 Definitions 53.2 Symbols and abbreviations 83.3 Keywords . 83.4 Conventions. 94 Overview 105 Media changer models. 125.1 Independent media changer 125.2 Attached media changer 125.3 Media changer elements 125.3.1 Elements overview. 125.3.2 Medium transport element . 135.3.3 Storage elem

16、ent. 145.3.4 Import/export element 145.3.5 Data transfer element 145.3.6 Element status maintenance requirements 145.4 Volume tag information 155.4.1 Volume tag overview 155.4.2 Primary and alternate volume tag information . 165.4.3 Volume tag information format. 165.5 TapeAlert information. 175.5.1

17、 TapeAlert introduction 175.5.2 TapeAlert log sense format 176 Commands for media changer logical units. 196.1 Summary of commands for independent media changers 196.2 Summary of commands for attached media changers 206.3 Commands allowed in the presence of various reservations. 216.4 EXCHANGE MEDIU

18、M command 236.5 INITIALIZE ELEMENT STATUS command . 246.6 INITIALIZE ELEMENT STATUS WITH RANGE command . 25Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iiPage6.7 MOVE MEDIUM c

19、ommands 266.8 POSITION TO ELEMENT command. 276.9 READ ATTRIBUTE command . 296.10 READ ELEMENT STATUS commands . 306.10.1 READ ELEMENT STATUS introduction 306.10.2 Element status data . 316.10.3 Element status page 336.10.4 Medium transport element descriptor 346.10.5 Storage element descriptor 366.1

20、0.6 Import/export element descriptor . 386.10.7 Data transfer element descriptor . 396.10.8 Identification descriptor 416.11 REQUEST VOLUME ELEMENT ADDRESS command 426.12 SEND VOLUME TAG command . 446.12.1 SEND VOLUME TAG introduction. 446.12.2 Send action codes . 456.12.3 SEND VOLUME TAG parameter

21、data. 466.13 WRITE ATTRIBUTE command . 477 Parameters 487.1 Diagnostic parameters. 487.2 Log parameters 487.2.1 Log page codes . 487.2.2 TapeAlert log page 497.3 Mode parameters. 507.3.1 Mode page codes 507.3.2 Device Capabilities mode page . 517.3.3 Element Address Assignment mode page. 537.3.4 Tra

22、nsport Geometry Parameters mode page 55AnnexA TapeAlert Flags . 56Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iiiPageTables1 Volume tag information format. 162 Volume Identif

23、ication Qualifier . 173 Commands for independent media changers . 194 Commands for attached media changers 205 SMC commands allowed in the presence of various reservations. 226 EXCHANGE MEDIUM command. 237 INITIALIZE ELEMENT STATUS command . 248 INITIALIZE ELEMENT STATUS WITH RANGE command . 259 MOV

24、E MEDIUM and MOVE MEDIUM ATTACHED command 2610 POSITION TO ELEMENT command . 2711 READ ATTRIBUTE command . 2912 READ ELEMENT STATUS equivalent to the phrase “it is strongly recommended.“ 3.4 Conventions Certain words and terms used in this standard have a specific meaning beyond the normal English m

25、eaning. These words and terms are defined either in or in the text where they first appear. Names of commands, statuses, sense keys, additional sense codes, and additional sense code qualifiers are in all uppercase (e.g., REQUEST SENSE). Field names and bit names are in SMALL CAPS. Lower case is use

26、d for words having the normal English meaning. Fields containing only one bit are usually referred to as the name bit instead of the name field. Numbers that are not immediately followed by lowercase b or h are decimal values. Numbers immediately followed by lowercase b (xxb) are binary values. Numb

27、ers or upper case letters immediately followed by lowercase h (xxh) are hexadecimal values. Lists sequenced by letters (e.g., a-red, b-blue, c-green) show no priority relationship between the listed items. Numbered lists (e.g., 1-red, 2-blue, 3-green) show a priority ordering between the listed item

28、s. If a conflict arises between text, tables, or figures, the order of precedence to resolve the conflicts is text; then tables; and finally figures. Not all tables or figures are fully described in the text. Tables show data format and values. NOTES do not constitute any requirements for implemento

29、rs. Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI INCITS 382-2004 10 4 Overview The SCSI media changer device class specifies a logical unit that is involved, primarily, w

30、ith the movement of removable volumes in a controlled environment without human intervention. The SCSI device classes that provide for removable volumes are block, multimedia and sequential. (See the SBC-2, MMC-4 and SSC-2 standards.) A media changer logical unit receives commands to move volumes be

31、tween various element types in the element address space of the media changer. The element types are storage, data transfer, medium transport, and import/export. A volume handling robotics subsystem, addressed as a medium transport element, moves volumes within a media changer. Volumes may also be m

32、oved between media changers with interconnected import/export ports. A media changer logical unit maintains an inventory of volumes and the element addresses at which they may be found. The media changer logical unit reports this inventory when requested and identifies the element addresses assigned

33、 to different types of elements. Different levels of sophistication may be implemented in how this inventory is managed, reported, detected and maintained. The elements in a media changer may be reserved to different SCSI initiator ports. For example, one data transfer element may be reserved for ex

34、clusive use by one SCSI initiator port. The data transfer device, located at that data transfer element, may then be attached to various systems for their use. In some cases, the data transfer device associated with a data transfer element may not be a SCSI device. The split between load and unload

35、control of the medium and read and write control by a data transfer device is a key feature of this device class. The mechanism for coordinating this kind of sophisticated activity is not specified in this standard. The media changer device class provides the means for mount/dismount management only

36、. Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI INCITS 382-2004 11 Figure 2 shows an example of an independent media changer. The data transfer elements (data transfer dev

37、ices) shown may be any type of removable media device such as a tape drive, disk drive or optical drive. Supporting multiple types of removable media within the same media changer is also permitted. Also, the ports on each data transfer device may or may not attach to the same service delivery subsy

38、stem and the interfaces to the data transfer devices may or may not be SCSI target ports. The number and arrangement of elements is arbitrary. Import/Export ElementStorage ElementsData Transport ElementsMedium TransportElementSCSITargetPortPortPortMediaChangerLogical UnitFigure 2 - Example independe

39、nt media changer device The independent changer model applies to implementations where the media changer is addressed as a separate logical unit. The logical unit for the media changer may be accessed via the same SCSI target port as the data transfer device, or via a different SCSI target port. Thi

40、s type of media changer may support more than one data transfer element. The attached media changer model permits a subset of the functions of an independent changer to be incorporated directly into a data transfer device. Only one data transfer element is permitted. In this case, only one logical u

41、nit is used to access all functions. A media changer moves volumes among the elements accessible to it on command from an application client. Media changers shall be capable of reporting the full or empty status of any element. Copyright American National Standards Institute Provided by IHS under li

42、cense with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI INCITS 382-2004 12 5 Media changer models 5.1 Independent media changer An independent media changer is a device server that returns 8h in the PERIPHERAL DEVICE TYPE field (see SPC-2) of INQUIRY co

43、mmand response data. Independent media changers respond to a LUN different from those used by a data transfer device. Communication with a data transfer device may use the same service delivery subsystem as the media changer device, or a different SCSI service delivery subsystem. Data transfer devic

44、es that are not SCSI devices are also permitted. Multiple data transfer devices may be attached to an independent changer. If a data transfer device served by the media changer is a SCSI device, the data transfer device may be addressed on a SCSI service delivery subsystem though the same SCSI targe

45、t port as the media changer but with a different LUN. The data transfer device may also be addressed through independent SCSI target ports and any LUN on the same or a different service delivery subsystem. The READ ELEMENT STATUS command response data page for each data transfer element may provide

46、the identity of the data transfer device serviced by a media changer device. This support is optional since a data transfer device is not required to be a SCSI device. 5.2 Attached media changer An attached media changer is part of a device server that sets the MCHNGR bit to one in its standard INQU

47、IRY data (see SPC-2). Attached media changers respond to the same LUN as a data transfer device that is not a media changer. In an attached media changer, the PERIPHERAL DEVICE TYPE field of standard INQUIRY data returns the type of the data transfer device. Two media changer commands, READ ELEMENT

48、STATUS ATTACHED and MOVE MEDIUM ATTACHED are added to the command set of the data transfer device. The other commands available depend on the model for the data transfer device. 5.3 Media changer elements 5.3.1 Elements overview A media changer has an address space separate and distinct from the phy

49、sical address space of a SCSI-3 service delivery subsystem. The term element is used throughout this standard to refer to one member of the media changer address space. Within a media changer, the element addresses are a set of physical locations and mechanisms within the scope of a media changer device. Each element is an instance of one of four element types: a) medium transport element; b) s