sg_ident(8)

1SG_IDENT(8)                        SG3_UTILS                       SG_IDENT(8)
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NAME

6       sg_ident - send SCSI REPORT/SET IDENTIFYING INFORMATION command
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SYNOPSIS

9       sg_ident  [--ascii]  [--clear]  [--help]  [--itype=IT]  [--raw] [--set]
10       [--verbose] [--version] DEVICE
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DESCRIPTION

13       Send a SCSI REPORT IDENTIFYING INFORMATION or SET IDENTIFYING  INFORMA‐
14       TION command to DEVICE. Prior to SPC-4 (revision 7) these commands were
15       called REPORT DEVICE IDENTIFIER and SET DEVICE IDENTIFIER respectively.
16       SCSI devices that support these two commands allow users to write (set)
17       identifying information and report it back  at  some  later  time.  The
18       information  is  persistent  (i.e.  stored  on some non-volatile medium
19       within the SCSI device that will survive a power outage).
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21       Typically the space allocated for the  information  is  limited:  SPC-4
22       (revision  7) states that for information type 0, the minimum length is
23       64 bytes and the maximum is 512 bytes. For other information  types  (1
24       to  126  inclusive)  the  maximum length is 256 bytes. Also information
25       types 1 to 126 (inclusive)  should  contain  a  null  terminated  UTF-8
26       string. The author has seen older disks that only support 16 bytes.
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28       The  default  action  when no options are given is to invoke the Report
29       Identifying Information command with the information type defaulting to
30       zero.  Error  reports are sent to stderr. By default the information is
31       shown in ASCII-HEX (up to 16 bytes per line) with an ASCII  representa‐
32       tion to the right with dots replacing non printable characters.
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OPTIONS

35       Arguments to long options are mandatory for short options as well.
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37       -A, --ascii
38              invokes  the  Report Identifying Information command and if any‐
39              thing is found interprets it as ASCII (or UTF-8 depending on the
40              locale) and prints the information to stdout.
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42       -C, --clear
43              invokes the Set Identifying Information command with an informa‐
44              tion length of zero. This has the effect of clearing the  exist‐
45              ing information.
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47       -h, --help
48              output the usage message then exit.
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50       -i, --itype=IT
51              where  IT is the information type. Defaults to zero. The maximum
52              value is 127 which is special and cannot be used with  --set  or
53              --clear.  The  information type of 127 (if supported) causes the
54              REPORT IDENTIFYING INFORMATION command to respond with a list of
55              available  information types and their maximum lengths in bytes.
56              The odd numbered information types between 3 and 125 (inclusive)
57              are not to be used (as they clash with the SCC-2 standard).
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59       -r, --raw
60              invokes  the  Report Identifying information command and if any‐
61              thing is found sends the information (which may  be  binary)  to
62              stdout. Nothing else is sent to stdout however error reports, if
63              any, are sent to stderr.
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65       -S, --set
66              first reads stdin until an EOF is detected then invokes the  Set
67              Identifying  Information  command  to  set what has been fetched
68              from stdin as the information. The amount of data read  must  be
69              between 1 and 512 bytes length (inclusive).
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71       -v, --verbose
72              increase the level of verbosity, (i.e. debug output).
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74       -V, --version
75              print the version string and then exit.
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77       This  utility  permits users to write their own identifying information
78       to their SCSI devices. There are several other types of descriptors (or
79       designators)  that  the  user  cannot  change.  These  include the SCSI
80       INQUIRY command with its standard  vendor  and  product  identification
81       strings and the product revision level; plus the large amount of infor‐
82       mation provided by the "Device Identification" VPD page  (see  sg_vpd).
83       There  is  also the READ MEDIA SERIAL NUMBER command (see sg_rmsn). The
84       MMC-4 command set for CD and DVDs has a "media serial  number"  feature
85       (0x109)  [and  a  "logical  unit  serial number" feature]. These can be
86       viewed with the sg_get_config utility.
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EXAMPLES

89       First, to see if there is  an  existing  information  whose  format  is
90       unknown (for information type 0), use no options:
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92         # sg_ident /dev/sdb
93          00     31 32 33 34 35 36 37 38  39 30          1234567890
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95       If it is ASCII then it can printed as such:
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97         # sg_ident --ascii /dev/sdb
98         1234567890
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100       The  information  can be copied to a file, cleared and then re-asserted
101       with this sequence:
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103         # sg_ident --raw /dev/sdb > t
104         # sg_ident --clear /dev/sdb
105         # cat t | sg_ident --set /dev/sdb
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EXIT STATUS

108       The exit status of sg_ident is 0 when it is successful.  Otherwise  see
109       the sg3_utils(8) man page.
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AUTHORS

112       Written by Douglas Gilbert.
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REPORTING BUGS

115       Report bugs to <dgilbert at interlog dot com>.
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COPYRIGHT

118       Copyright © 2005-2012 Douglas Gilbert
119       This  software is distributed under a FreeBSD license. There is NO war‐
120       ranty; not even for MERCHANTABILITY or FITNESS FOR  A  PARTICULAR  PUR‐
121       POSE.
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