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       sg_vpd  -  fetches  Vital Product Data (VPD) pages using a SCSI INQUIRY


       sg_vpd [--enumerate] [--help] [--hex] [--ident] [--long] [--maxlen=LEN]
       [--page=PG] [--quiet] [--raw] [--verbose] [--version] DEVICE


       This  utility  fetches  a  Vital  Product  Data  page and decodes it or
       outputs it in ASCII hexadecimal or binary. VPD pages are fetched with a
       SCSI INQUIRY command.

       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

       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

       -e, --enumerate
              list the names of the known VPD pages, first the standard pages,
              then  the  vendor  specific  pages.  Each  group  is  sorted  in
              abbreviation order. The DEVICE and other options are ignored and
              this utility exits afte listing the VPD page names.

       -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.

       -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
              logical  unit  designator  is  decoded.  In the latter case this
              option has the same effect as ’--quiet --page=di_lu’.

       -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
              argument can either be an abbreviation, a number or  a  pair  or
              numbers  separated by a comma. The VPD page abbreviations 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 are given  the  second  number  indicates  which  vendor
              specific  VPD  page  to decode when several pages share the same
              VPD page number. If this option is not given (nor ’-i’, ’-l’ nor
              ’-V’)  then  the "Supported VPD pages" (0x0) VPD page is fetched
              and decoded.

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

       -r, --raw
              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.

       -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
       settings 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.


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


       Written by Doug Gilbert


       Report bugs to <dgilbert at interlog dot com>.


       Copyright © 2006-2008 Douglas Gilbert
       This  software  is  distributed  under  a  FreeBSD license. There is NO
       warranty; not even for MERCHANTABILITY  or  FITNESS  FOR  A  PARTICULAR


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