SG_IDENT(8)							     SG3_UTILS							       SG_IDENT(8)

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 (revison 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 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	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 (C) 2005-2007 Douglas Gilbert
       This  software  is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
       POSE.

SEE ALSO

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

sg3_utils-1.23							   January 2007 						       SG_IDENT(8)