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man pages section 8: System Administration Commands

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Updated: Wednesday, July 27, 2022

sg_vpd (8)


sg_vpd - fetch SCSI VPD page and/or decode its response


sg_vpd  [--all]  [--enumerate]  [--examine]  [--force] [--help] [--hex]
[--ident] [--inhex=FN] [--long]  [--maxlen=LEN]  [--page=PG]  [--quiet]
[--raw] [--vendor=VP] [--verbose] [--version] [DEVICE]


SG_VPD(8)                          SG3_UTILS                         SG_VPD(8)

       sg_vpd - fetch SCSI VPD page and/or decode its response

       sg_vpd  [--all]  [--enumerate]  [--examine]  [--force] [--help] [--hex]
       [--ident] [--inhex=FN] [--long]  [--maxlen=LEN]  [--page=PG]  [--quiet]
       [--raw] [--vendor=VP] [--verbose] [--version] [DEVICE]

       This  utility, when DEVICE is given, fetches a Vital Product Data (VPD)
       page and decodes it or outputs it in ASCII hexadecimal or  binary.  VPD
       pages are fetched with a SCSI INQUIRY command.

       Alternatively  the  --inhex=FN  option can be given. In this case FN is
       assumed to be a file name ('-' for stdin) containing ASCII  hexadecimal
       representing  a  VPD  page  response. If the --raw option is also given
       then binary input is assumed (rather than ASCII hexadecimal).

       Probably the most important page is the Device Identification VPD  page
       (page  number:  0x83).  Since  SPC-3,  support  for  this page has been
       flagged as mandatory. This page can be fetched  by  using  the  --ident

       The reference document used for interpreting VPD pages (and the INQUIRY
       standard response) is T10/BSR INCITS 502 Revision  22  which  is  draft
       SPC-5 revision 19, 22 April 2019. It can be found at http://www.t10.org

       When no options are given, other than a DEVICE, then the "Supported VPD
       pages" (0x0) VPD page is fetched and decoded.

       Arguments to long options are mandatory for short options as well.  The
       options are arranged in alphabetical order based  on  the  long  option

       -a, --all
              decode  all  VPD  pages.  When  used with DEVICE the pages to be
              decoded are found in the "Supported VPD pages" VPD  page.  Pages
              that  cannot  be  decoded  are  displayed in hex; add the --long
              option to have ASCII displayed to the right of each line of hex.
              If this option is used with the --inhex=FN option then the  file
              FN  is  assumed  to contain 1 or more VPD pages (in ASCII hex or
              binary).  Decoding continues until the file is exhausted (or  an
              error  occurs).  Sanity  checks  are  applied on each VPD page's
              length and the ascending order of VPD page numbers (required  by
              SPC-4) so bad data may be detected.
              If  the  --page=PG  option  is also given then no VPD page whose
              page number is greater than PG (or its  numeric  equivalent)  is

       -e, --enumerate
              list  the names of the known VPD pages, first the standard pages
              (i.e.  those defined by T10), then the  vendor  specific  pages.
              Each  group is sorted in abbreviation order. The DEVICE and most
              other options are ignored and this utility exits  after  listing
              the VPD page names. May be used together with --page=PG where PG
              is numeric. If so, it searches for the summary lines of all  VPD
              pages  whose  number matches PG. May be used with --vendor=VP to
              restrict output to known vendor specific pages for  vendor/prod-
              uct VP.

       -E, --examine
              scan  part of all of the VPD space (from 0x0 to 0xff) and output
              any pages found. This option ignores the contents  of  VPD  page
              0x0 which should contain a list of all supported VPD pages. How-
              ever some vendors either forget to list some standard  pages  or
              perhaps  purposely don't list vendor specific pages which are in
              the range 0xc0 to 0xff.
              If the --page=PG option is not given and this  option  is  given
              once  then  the scan is from VPD page number 0x80 to 0xff inclu-
              sive. If the --page=PG option is given then  the  scan  is  from
              0x80  to  PG  inclusive.  If this option is given twice then the
              scan starts at VPD page 0x0.
              The sdparm utility which lists mode and VPD  pages  also  has  a
              --examine option will similar functionility.

       -f, --force
              As  a  sanity  check,  the normal action when fetching VPD pages
              other than page 0x0 (the "Supported VPD pages" VPD page), is  to
              first  fetch  page  0x0 and only if the requested page is one of
              the supported pages, to go ahead and fetch the requested page.
              When this option is given, skip checking of VPD page 0x0  before
              accessing  the  requested  VPD page. The prior check of VPD page
              0x0 is known to crash certain USB devices, so use with care.

       -h, --help
              outputs the usage message summarizing command line options  then
              exits.  Ignores DEVICE if given.

       -H, --hex
              outputs the requested VPD page in ASCII hexadecimal. Can be used
              multiple times, see section on the ATA information vpd page.
              To generate output suitable for placing in a file  that  can  be
              used  by  a later invocation with the --inhex=FN option, use the
              '-HHHH'  option  (e.g.  'sg_vpd   -p   di   -HHHH   /dev/sg3   >
              dev_id.hex').  The  reason  '-HHHH'  is  used  is  to  flag that
              unadorned hexadecimal (without other text or address offsets) is
              sent to stdout.

       -i, --ident
              decode the device identification (0x83) VPD page. When used once
              this option has the same effect as '--page=di'. When  use  twice
              then the short form of the device identification VPD page's log-
              ical unit designator is decoded. In the latter case this  option
              has the same effect as '--quiet --page=di_lu'.

       -I, --inhex=FN
              FN  is  expected to be a file name (or '-' for stdin) which con-
              tains ASCII hexadecimal or binary representing a VPD page (or  a
              standard  INQUIRY)  response. This utility will then decode that
              response. It is preferable to also supply the --page=PG  option,
              if  not  this  utility  will attempt to guess which VPD page (or
              standard INQUIRY) the response is associated with. The hexadeci-
              mal should be arranged as 1 or 2 digits representing a byte each
              of which is whitespace or comma  separated.  Anything  from  and
              including  a  hash  mark  to  the end of line is ignored. If the
              --raw option is also given then FN is treated as binary.

       -l, --long
              when decoding some VPD pages, give a  little  more  output.  For
              example  the  ATA  Information VPD page only shows the signature
              (in hex) and the IDENTIFY (PACKET) DEVICE  (in  hex)  when  this
              option is given.

       -m, --maxlen=LEN
              where  LEN  is  the  (maximum)  response  length in bytes. It is
              placed in the cdb's "allocation length" field. If not given  (or
              LEN  is  zero)  then 252 is used (apart from the ATA Information
              VPD page which defaults to 572) and, if the  response  indicates
              this value is insufficient, another INQUIRY command is sent with
              a larger value in the cdb's "allocation length" field.  If  this
              option  is given and LEN is greater than 0 then only one INQUIRY
              command is sent. Since many simple devices implement the INQUIRY
              command  badly  (and  do  not support VPD pages) then the safest
              value to use for LEN is 36. See the sg_inq man page for the more

       -p, --page=PG
              where  PG  is the VPD page to be decoded or output. The PG argu-
              ment can either be an abbreviation, a number or a pair  or  num-
              bers/abbreviations  separated by a comma. The VPD page abbrevia-
              tions can be seen by using the --enumerate option. If  a  number
              is given it is assumed to be decimal unless it has a hexadecimal
              indicator which is either a leading '0x' or a trailing  'h'.  If
              one  number is given then it is assumed to be a VPD page number.
              If two numbers (or abbreviations) are given then the second  one
              is  the  same as VP (see the --vendor=VP option). If this option
              is not given (nor '-i', '-l' nor '-V') then the  "Supported  VPD
              pages"  (0x0)  VPD page is fetched and decoded. If PG is '-1' or
              'sinq' then the standard INQUIRY response is output. This option
              may also be used with the --enumerate (see its description).
              If  PG  is not found in the 'Supported VPD pages' VPD page (0x0)
              then EDOM is returned. To bypass  this  check  use  the  --force

       -q, --quiet
              suppress the amount of decoding output.

       -r, --raw
              if  not  used  with --inhex=FN then output requested VPD page in
              binary.  The output should be piped to a file or another utility
              when  this  option  is  used.  The binary is sent to stdout, and
              errors are sent to stderr.
              if used with --inhex=FN then the contents of FN  is  treated  as

       -M, --vendor=VP
              where  VP is a vendor (e.g. "sea" for Seagate) or vendor/product
              acronym (e.g. "hp3par" for the 3PAR array from HP). Many vendors
              have re-used the numbers at the beginning of the vendor specific
              VPD page range (e.g.  page 0xc0) and this option  is  a  way  of
              selecting  only those which are of interest. Using a VP of "xxx"
              will list the available acronyms.
              If this option is used with --page=PG and PG is an acronym  then
              this option is ignored. If PG is a number (e.g. 0xc0) then VP is
              used to choose the which vendor specific page (e.g. sharing page
              number 0xc0) to decode.

       -v, --verbose
              increases the level or verbosity.

       -V, --version
              print out version string then exit.

       This  VPD page (0x89 or 'ai') is defined by the SCSI to ATA Translation
       standard. It contains information about the SAT layer, the  "signature"
       of  the ATA device and the response to the ATA IDENTIFY (PACKET) DEVICE
       command. The latter part has 512 bytes of identity, capability and set-
       tings  data  which  the  hdparm utility is capable of decoding (so this
       utility doesn't decode it).

       To unclutter the output for this page, the signature and  the  IDENTIFY
       (PACKET)  DEVICE  response  are not output unless the --long option (or
       --hex or --raw) are given. When the --long option is given the IDENTIFY
       (PACKET)  DEVICE  response  is  output  as 256 (16 bit) words as is the
       fashion for ATA devices. To see that response as a string of bytes  use
       the  '-HH'  option.  To format the output suitable for hdparm to decode
       use either the '-HHH' or '-rr' option. For example if  'dev/sdb'  is  a
       SATA  disk  behind  a  SAT  layer then this command: 'sg_vpd -p ai -HHH
       /dev/sdb | hdparm --Istdin' should decode  the  ATA  IDENTIFY  (PACKET)
       DEVICE response.

       See attributes(7) for descriptions of the following attributes:

       |Availability   | system/storage/sg3_utils |
       |Stability      | Pass-through uncommitted |

       Since  some  VPD  pages (e.g. the Extended INQUIRY page) depend on set-
       tings in the standard  INQUIRY  response,  then  the  standard  INQUIRY
       response  is  output  as  a  pseudo  VPD page when PG is set to '-1' or
       'sinq'. Also the decoding of some fields  (e.g.  the  Extended  INQUIRY
       page's  SPT  field) is expanded when the '--long' option is given using
       the standard INQUIRY response information (e.g. the PDT and the PROTECT

       In  the  2.4  series of Linux kernels the DEVICE must be a SCSI generic
       (sg) device. In the 2.6 series block  devices  (e.g.  disks  and  ATAPI
       DVDs) can also be specified. For example "sg_inq /dev/sda" will work in
       the 2.6 series kernels. From lk 2.6.6 other SCSI  "char"  device  names
       may be used as well (e.g. "/dev/st0m").

       The  DEVICE  is  opened  with  a  read-only flag (e.g. in Unix with the
       O_RDONLY flag).

       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source was downloaded from  http://sg.danny.cz/sg/p/sg3_utils-1.46.tgz.

       Further information about this software can be found on the open source
       community website at http://sg.danny.cz/sg/sg3_utils.html.

       The exit status of sg_vpd is 0 when it is successful. Otherwise see the
       sg3_utils(8) man page.

       The examples in this page use Linux device names. For  suitable  device
       names  in  other  supported  Operating Systems see the sg3_utils(8) man

       To see the VPD pages that a device supports, use with no  options.  The
       command line invocation is shown first followed by a typical response:

          # sg_vpd /dev/sdb
       Supported VPD pages VPD page:
         Supported VPD pages [sv]
         Unit serial number [sn]
         Device identification [di]
         Extended inquiry data [ei]
         Block limits (SBC) [bl]

       To  see  the  VPD page numbers associated with each supported page then
       add the '--long' option to the above command line. To view a  VPD  page
       either its number or abbreviation can be given to the '--page=' option.
       The page name abbreviations are shown within square brackets above.  In
       the next example the Extended inquiry data VPD page is listed:

          # sg_vpd --page=ei /dev/sdb
       extended INQUIRY data VPD page:
         WU_SUP=0 CRD_SUP=0 NV_SUP=0 V_SUP=0
         P_I_I_SUP=0 LUICLR=0 R_SUP=0 CBCS=0
         Multi I_T nexus microcode download=0
         Extended self-test completion minutes=0
         POA_SUP=0 HRA_SUP=0 VSA_SUP=0

       To  check  if  any  protection  types  are  supported by a disk use the
       '--long' option on the Extended inquiry data VPD page:

          # sg_vpd --page=ei --long /dev/sdb
          extended INQUIRY data VPD page:
            SPT=1 [protection types 1 and 2 supported]

       Search for the name (and acronym) of all pages that share VPD page num-
       ber 0xb0 .

          # sg_vpd --page=0xb0 --enumerate
          Matching standard VPD pages:
            bl         0xb0      Block limits (SBC)
            oi         0xb0      OSD information
            sad        0xb0      Sequential access device capabilities (SSC)

       Some  examples follow using the "--all" option. Send an ASCII hexadeci-
       mal representation of all VPD pages to a file:

          # sg_vpd --all -HHHH /dev/sg3 > all_vpds.hex

       At some later time that file could be decoded with:

          # sg_vpd --all --inhex=all_vpds.hex

       To do the equivalent as the previous example but use a file  containing

          # sg_vpd --all --raw /dev/sg3 > all_vpds.bin
          # sg_vpd --all --raw --inhex=all_vpds.bin

       Notice  that "--raw" must be given with the second (--inhex) invocation
       to alert the utility that all_vpds.bin contains binary  as  it  assumes
       ASCII  hexadecimal  by  default.  Next we only decode T10 specified VPD
       pages excluding vendor specific VPD pages that  start  at  page  number

          # sg_vpd --all --page=0xbf --raw --inhex=all_vpds.bin

       Further       examples       can       be       found       on      the
       http://sg.danny.cz/sg/sg3_utils.html web page.

       Written by Douglas Gilbert

       Report bugs to <dgilbert at interlog dot com>.

       Copyright (C) 2006-2021 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO  war-
       ranty;  not  even  for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-

       sg_inq(sg3_utils), sg3_utils(sg3_utils), sdparm(sdparm), hdparm(hdparm)

sg3_utils-1.46                    March 2021                         SG_VPD(8)