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NAME

       sg_ident - sends a SCSI REPORT or 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 depending on
              the locale) 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 © 2005-2009 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)