NAME

       sg_ident - send SCSI REPORT/SET IDENTIFYING INFORMATION command

SYNOPSIS

       sg_ident [--ascii] [--clear] [--help] [--itype=IT] [--raw] [--set] [--verbose] [--version]
       DEVICE

DESCRIPTION

       Send a SCSI REPORT IDENTIFYING INFORMATION  or  SET  IDENTIFYING  INFORMATION  command  to
       DEVICE.  Prior  to  SPC-4 (revision 7) these commands were called REPORT DEVICE IDENTIFIER
       and SET DEVICE IDENTIFIER respectively. SCSI devices that support these two commands allow
       users  to  write  (set) identifying information and report it back at some later time. The
       information 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 information is limited: SPC-4 (revision 7) states
       that for information type 0, the minimum length is 64 bytes and the maximum is 512  bytes.
       For  other  information  types  (1 to 126 inclusive) the maximum length is 256 bytes. Also
       information types 1 to 126 (inclusive) should contain a null terminated UTF-8 string.  The
       author has seen older disks that only support 16 bytes.

       The  default  action  when  no  options  are  given  is  to  invoke the Report Identifying
       Information command with the information type defaulting to zero. Error reports  are  sent
       to stderr. By default the information is shown in ASCII-HEX (up to 16 bytes per line) with
       an ASCII representation to the right with dots replacing non printable characters.

OPTIONS

       Arguments to long options are mandatory for short options as well.

       -A, --ascii
              invokes the Report  Identifying  Information  command  and  if  anything  is  found
              interprets  it  as  ASCII  (or  UTF-8  which  is  locale  dependent) and prints the
              information to stdout.

       -C, --clear
              invokes the Set Identifying Information command with an information length of zero.
              This has the effect of clearing the existing information.

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

       -i, --itype=IT
              where  IT is the information type. Defaults to zero. The maximum value is 127 which
              is special and cannot be used with --set or --clear. The information  type  of  127
              (if  supported) causes the REPORT IDENTIFYING INFORMATION command to respond with a
              list of available information types and their maximum lengths  in  bytes.  The  odd
              numbered  information  types  between  3 and 125 (inclusive) are not to be used (as
              they clash with the SCC-2 standard).

       -r, --raw
              invokes the Report Identifying information command and if anything is  found  sends
              the  information  (which  may  be binary) to stdout. Nothing else is sent to stdout
              however error reports, if any, are sent to stderr.

       -S, --set
              first reads stdin until an  EOF  is  detected  then  invokes  the  Set  Identifying
              Information command to set what has been fetched from stdin as the information. The
              amount of data read must be between 1 and 512 bytes length (inclusive).

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

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

       This utility permits users to write  their  own  identifying  information  to  their  SCSI
       devices.  There  are  several  other  types  of descriptors (or designators) 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_vpd). There  is  also
       the  READ MEDIA SERIAL NUMBER command (see sg_rmsn). The MMC-4 command set for CD and DVDs
       has a "media serial number" feature (0x109) [and a "logical unit serial number"  feature].
       These can be viewed with the sg_get_config utility.

EXAMPLES

       First, to see if there is an existing information whose format is unknown (for information
       type 0), use no options:

         # sg_ident /dev/sdb
          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
         1234567890

       The information 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

EXIT STATUS

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

AUTHORS

       Written by Douglas Gilbert.

REPORTING BUGS

       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT

       Copyright © 2005-2018 Douglas Gilbert
       This  software  is distributed under a FreeBSD license. There is NO warranty; not even for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       sg_vpd(sg3_utils), sg_rmsn(sg3_utils), sg_get_config(sg3_utils)