man > sg_ident(8)

SG_IDENT(8)                                   SG3_UTILS                                  SG_IDENT(8)



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 DE‐
       VICE 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 informa‐
       tion 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 repre‐
       sentation 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 sup‐
              ported) causes the REPORT IDENTIFYING INFORMATION command to respond with  a  list  of
              available  information  types and their maximum lengths in bytes. The odd numbered in‐
              formation 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 Informa‐
              tion 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" fea‐
       ture  (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 MER‐
       CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO
       sg_vpd(sg3_utils), sg_rmsn(sg3_utils), sg_get_config(sg3_utils)



sg3_utils-1.43                               August 2018                                 SG_IDENT(8)