Provided by: sg3-utils_1.17-2_i386 bug


       sg_ident - report or set device identifier


       sg_ident  [--ascii]  [--clear]  [--help]  [--raw]  [--set]  [--verbose]
       [--version] <scsi_device>


       to the given device. SCSI devices that support these two commands allow
       users to write (set) an identifier and report it  back  at  some  later
       time.  The  identifier  is persistent (i.e. stored on some non-volatile
       medium within the SCSI device that will survive a power outage).

       Typically the space allocated for  the  identifier  is  limited:  SPC-4
       (revision  0)  states  the  maximum length is 512 bytes and all devices
       (that support these commands) shall support lengths up to 64 bytes. The
       author has seen older disks that only support 16 bytes.

       The  default  action  when no options are given is to invoke the Report
       Device Identifier command. Error reports are  sent  to  stderr.  If  no
       errors  occur  then  the  length of the device identifier is output (to
       stdout). This is followed by an ASCII-HEX rendering of each byte of the
       identifier  (up  to 16 bytes per line) which an ASCII representation to
       the right with dots replacing non printable characters.  each

       --ascii | -A
              invokes the Report Device Identifier command and if anything  is
              found  interprets  it  as  ASCII  (or  UTF-8  depending  on  the
              environment) and prints the identifier to stdout.

       --clear | -C
              invokes the Set Device Identifier  command  with  an  identifier
              length  of  zero.  This  has the effect of clearing the existing
              device identifier.

       --help | -h
              output the usage message then exit.

       --raw | -r
              invokes the Report Device Identifier command and if anything  is
              found  sends  the  identifier  (which  may be binary) to stdout.
              Nothing else is sent to stdout however error reports are sent to

       --set | -S
              first  read  stdin until an EOF is detected then invokes the Set
              Device Identifier command to set  what  has  been  fetched  from
              stdin  as the device identifier. The amount of data read must be
              between 1 and 512 bytes length (inclusive).

       --verbose | -v
              increase the level of verbosity, (i.e. debug output).

       --version | -V
              print the version string and then exit.

       This utility facilitates users writing their own identifiers  to  their
       SCSI  devices.  There  are  several other types of identifiers that the
       user cannot change. These include the SCSI  INQUIRY  command  with  its
       standard  vendor  and  product  identification  strings and the product
       revision level; plus the large amount of information  provided  by  the
       "Device  Identification" VPD page (see sg_inq).  There is also the READ
       MEDIA SERIAL NUMBER command (see sg_rmsn).  The MMC-4 command  set  for
       CDs  and  DVDs  has  a  "media  serial  number"  feature (0x109) [and a
       "logical unit  serial  number"  feature].  These  can  be  viewed  with

       When  this  utility  succeeds  its process exits with a status of 0; if
       problems are encountered the process status is 1 .


       First, to see if there is an existing device identifier whose format is
       unknown, use no options:

         # sg_ident /dev/sdb
         Reported device identifier length = 10
         Device identifier:
          00     31 32 33 34 35 36 37 38  39 30          1234567890

       If it is ASCII then it can printed as such:

         # sg_ident --ascii /dev/sdb
         Reported device identifier length = 10
         Device identifier:

       The  device  identifier  can  be copied to a file, cleared and then re-
       asserted with this sequence:

         # sg_ident --raw /dev/sdb > t
         # sg_ident --clear /dev/sdb
         # cat t | sg_ident --set /dev/sdb


       Written by Douglas Gilbert.


       Report bugs to <dgilbert at interlog dot com>.


       Copyright © 2005 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), sg_rmsn(sg3_utils), sg_get_config(sg3_utils)