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man pages section 8: System Administration Commands

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Updated: Wednesday, July 27, 2022

sg_sat_identify (8)


sg_sat_identify - send ATA IDENTIFY DEVICE command via SCSI to ATA Translation (SAT) layer


sg_sat_identify  [--ck_cond]  [--extend]  [--help]  [--hex]   [--ident]
[--len=CLEN]  [--packet]  [--raw]  [--readonly] [--verbose] [--version]


SG_SAT_IDENTIFY(8)                 SG3_UTILS                SG_SAT_IDENTIFY(8)

       sg_sat_identify  -  send  ATA  IDENTIFY  DEVICE command via SCSI to ATA
       Translation (SAT) layer

       sg_sat_identify  [--ck_cond]  [--extend]  [--help]  [--hex]   [--ident]
       [--len=CLEN]  [--packet]  [--raw]  [--readonly] [--verbose] [--version]

       This utility sends either an ATA IDENTIFY  DEVICE  command  or  an  ATA
       IDENTIFY  PACKET DEVICE command to DEVICE and outputs the response. The
       devices that respond to these commands are ATA disks and ATAPI  devices
       respectively.   Rather  than send these commands directly to the device
       they are sent via a SCSI transport which is assumed to contain  a  SCSI
       to  ATA Translation (SAT) Layer (SATL). The SATL may be in an operating
       system driver, in host bus adapter firmware or in some external  enclo-

       The SAT standard (SAT ANSI INCITS 431-2007, prior draft: sat-r09.pdf at
       www.t10.org) defines two SCSI "ATA PASS-THROUGH" commands: one using  a
       16  byte  "cdb" and the other with a 12 byte cdb. This utility defaults
       to using the 16 byte cdb variant. SAT-4 revision 5 added  a  SCSI  "ATA
       PASS-THROUGH(32)"  command.  SAT-2  and  SAT-3  are now also standards:
       SAT-2 ANSI INCITS 465-2010 and SAT-3 ANSI INCITS 517-2015 .  The  SAT-4
       project   is   near  standardization  and  the  most  recent  draft  is
       sat4r06.pdf .

       Arguments to long options are mandatory for short options as well.

       -c, --ck_cond
              sets the CK_COND bit in  the  ATA  PASS-THROUGH  SCSI  cdb.  The
              default  setting  is  clear  (i.e.  0). When set the SATL should
              yield a sense buffer containing a ATA  Result  descriptor  irre-
              spective  of whether the command succeeded or failed. When clear
              the SATL should only yield  a  sense  buffer  containing  a  ATA
              Result descriptor if the command failed.

       -e, --extend
              sets  the  EXTEND  bit  in  the  ATA  PASS-THROUGH SCSI cdb. The
              default setting is clear (i.e. 0). When set a 48 bit LBA command
              is sent to the device. This option has no effect when --len=12.

       -h, --help
              outputs  the usage message summarizing command line options then
              exits. Ignores DEVICE if given.

       -H, --hex
              outputs the ATA IDENTIFY (PACKET) DEVICE response  in  hex.  The
              default  action (i.e. without any '-H' options) is to output the
              response in hex, grouped in 16 bit words  (i.e.  the  ATA  stan-
              dard's  preference).  When given once, the response is output in
              ASCII hex bytes (i.e.  the  SCSI  standard's  preference).  When
              given twice (i.e. '-HH') the output is in hex, grouped in 16 bit
              words, the same as the default but without a header. When  given
              thrice  (i.e.  '-HHH')  the  output is in hex, grouped in 16 bit
              words, in a format that is acceptable for 'hdparm  --Istdin'  to
              process. '-HHHH' simply outputs hex data bytes, space separated,
              16 per line.

       -i, --ident
              outputs the World Wide Name (WWN) of the device. This should  be
              a  NAA-5  64 bit number. It is output in hex prefixed with "0x".
              If not available then "0x0000000000000000" is output. The equiv-
              alent  for a SCSI disk (i.e. its logical unit name) can be found
              with "sg_vpd -ii".

       -l, --len=CLEN
              CLEN this is the length  of  the  SCSI  cdb  used  for  the  ATA
              PASS-THROUGH  command.   CLEN  can  either  be 12, 16 or 32. The
              default is 16. The larger cdb sizes are needed for  48  bit  LBA
              addressing  of  ATA devices. The ATA Auxiliary and ICC registers
              are only conveyed with the 32 byte cdb variant.

       -p, --packet
              send an ATA IDENTIFY PACKET DEVICE command (via the  SATL).  The
              default  action  is to send an ATA IDENTIFY DEVICE command. Note
              that the ATAPI specification by T13 (i.e. the PACKET  interface)
              is now obsolete.

       -r, --raw
              output  the ATA IDENTIFY (PACKET) DEVICE response in binary. The
              output should be piped to a file or another  utility  when  this
              option  is  used.   The binary is sent to stdout, and errors are
              sent to stderr.

       -R, --readonly
              open the DEVICE read-only (e.g. in Unix with the O_RDONLY flag).
              The default is to open it read-write.

       -v, --verbose
              increases the level or verbosity.

       -V, --version
              print out version string

       See attributes(7) for descriptions of the following attributes:

       |Availability   | system/storage/sg3_utils |
       |Stability      | Pass-through uncommitted |

       Since  the  response  to  the  IDENTIFY (PACKET) DEVICE command is very
       important for the correct use of an ATA(PI) device  (and  is  typically
       the  first  command sent), a SATL should provide an ATA Information VPD
       page which contains the similar information.

       The SCSI ATA PASS-THROUGH (12) command's opcode is 0xa1 and it  clashes
       with  the  MMC set's BLANK command used by cd/dvd writers. So a SATL in
       front of an ATAPI device that uses MMC (i.e. has peripheral device type
       5)  probably  should  treat  opcode 0xa1 as a BLANK command and send it
       through to the cd/dvd drive. The ATA PASS-THROUGH (16) command's opcode
       (0x85) does not clash with anything so it is a better choice.

       Prior  to Linux kernel 2.6.29 USB mass storage limited sense data to 18
       bytes  which  made  the  --ck_cond  option  yield  strange  (truncated)

       Source  code  for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-

       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source was downloaded from  http://sg.danny.cz/sg/p/sg3_utils-1.46.tgz.

       Further information about this software can be found on the open source
       community website at http://sg.danny.cz/sg/sg3_utils.html.

       These examples use Linux  device  names  and  a  Linux  utility  called
       hdparm.  For suitable device names in other supported Operating Systems
       see the sg3_utils(8) man page.

       In this example /dev/sdb is a SATA 2.5" disk connected via a USB  (type
       C  connector) dongle that implements the UAS (USB attached SCSI) proto-
       col (also known as UASP). UAS is a vast improvement over the  USB  mass
       storage class.

           # sg_sat_identify /dev/sdb
       Response for IDENTIFY DEVICE ATA command:
        00   0c5a 3fff c837 0010 0000 0000 003f 0000  .Z ?. .7 .. .. .. .? ..

       The  hexadecimal  ASCII  (with  plain  ASCII  to  the  right) output is
       abridged to a single line (i.e. the first 16 bytes (or 8  words)).  Now
       to decode some of that ATA Identify response. First sg_inq can decode a
       few strings:

           # sg_sat_identify -HHHH /dev/sdb | sg_inq --ata -I -
       ATA device: model, serial number and firmware revision:
         ST9500420AS     5VJCE6R7 0002SDM1

       For a lot more details, the hdparm utility is a good choice:

           # sg_sat_identify -HHH /dev/sdb | hdparm --Istdin
       ATA device, with non-removable media
               Model Number:       ST9500420AS
               Serial Number:      5VJCE6R7
               Firmware Revision:  0002SDM1
               Transport:          Serial

       There are about 80 more lines of details  decoded  by  hdparm  in  this
       case.   Notice  the difference in the number of "H" options: three give
       an unadorned hex output arranged in (little endian) words (i.e. 16 bits
       each)  while  four  "H"  options  give an unadorned hex output in bytes
       (i.e. 8 bits each).

       The exit status of sg_sat_identify is 0 when it is  successful.  Other-
       wise see the sg3_utils(8) man page.

       Written by Douglas Gilbert

       Report bugs to <dgilbert at interlog dot com>.

       Copyright (C) 2006-2020 Douglas Gilbert
       This  software is distributed under a FreeBSD license. There is NO war-
       ranty; not even for MERCHANTABILITY or FITNESS FOR  A  PARTICULAR  PUR-

       sg_vpd(sg3_utils), sg_inq(sg3_utils), sdparm(sdparm), hdparm(hdparm)

sg3_utils-1.45                   January 2020               SG_SAT_IDENTIFY(8)