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

Provided by: sg3-utils_1.46-3ubuntu4_amd64

NAME

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

SYNOPSIS

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

DESCRIPTION

       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 enclosure.

       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 .

OPTIONS

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 irrespective 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 standard'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
equivalent 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

NOTES

       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) results.

EXAMPLES

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) protocol (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
Standards:
....

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).

EXIT STATUS

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

AUTHOR

       Written by Douglas Gilbert

REPORTING BUGS

       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT

       Copyright © 2006-2020 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO warranty; not even for  MERCHANTABILITY
       or FITNESS FOR A PARTICULAR PURPOSE.