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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] [--ver-
     bose] [--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  de-
     vices  that support these two commands allow users to write (set) identify-
     ing 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  (revi-
     sion  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  inclu-
     sive) the maximum length is 256 bytes. Also information types 1 to 126 (in-
     clusive) 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 Iden-
     tifying 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 infor-
	    mation.

     -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  RE-
	    PORT  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 desig-
     nators) 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  "De-
     vice  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 (C) 2005-2018 Douglas Gilbert
     This software is distributed under a BSD-2-Clause license. There is NO war-
     ranty; 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)

sg3_utils-1.43			   August 2018			     SG_IDENT(8)

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