Ubuntu Manpage: sg_ident - send SCSI REPORT/SET IDENTIFYING INFORMATION command

Provided by: sg3-utils_1.36-1ubuntu1_amd64

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 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 © 2005-2012 Douglas Gilbert
       This  software  is distributed under a FreeBSD license. There is NO warranty; not even for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.