sg_sat_identify - sends a ATA IDENTIFY (PACKET) DEVICE command via a
SCSI to ATA Translation (SAT) layer
sg_sat_identify [--ck_cond] [--extend] [--help] [--hex] [--len=16|12]
[--packet] [--raw] [--verbose] [--version] DEVICE
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 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
The SATL may be in an operating system driver, in host bus adapter
firmware or in some external enclosure.
Arguments to long options are mandatory for short options as well.
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.
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.
outputs the usage message summarizing command line options then
exits. Ignores DEVICE if given.
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
-l, --len=16 | 12
this is the length of the SCSI cdb used for the ATA PASS-THROUGH
commands. The argument can either be 16 or 12. The default is
16. The larger cdb size is needed for 48 bit LBA addressing of
ATA devices. On the other hand some SCSI transports cannot
convey SCSI commands longer than 12 bytes.
send an ATA IDENTIFY PACKET DEVICE command (via the SATL). The
default action is to send an ATA IDENTIFY DEVICE command.
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.
increases the level or verbosity.
print out version string
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.
In the 2.4 series of Linux kernels the DEVICE must be a SCSI generic
(sg) device. In the 2.6 series block devices (e.g. disks and ATAPI
DVDs) can also be specified. For example "sg_inq /dev/sda" will work in
the 2.6 series kernels. From lk 2.6.6 other SCSI "char" device names
may be used as well (e.g. "/dev/st0m").
The exit status of sg_sat_identify is 0 when it is successful.
Otherwise see the sg3_utils(8) man page.
Written by Doug Gilbert
Report bugs to <dgilbert at interlog dot com>.
Copyright © 2006-2007 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
sg_vpd(sg3_utils), sg_inq(sg3_utils), sdparm(sdparm), hdparm(hdparm)