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

Provided by: sg3-utils_1.46-1build1_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.