SG_SAT_IDENTIFY(8) SG3_UTILS SG_SAT_IDENTIFY(8)
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] [--indent] [--len={16|12}] [--packet] [--raw] [--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-2 is also a standard:
SAT-2 ANSI INCITS 465-2010 and the draft prior to that is sat2r09.pdf . The SAT/-3 project has started and the most recent draft is
sat3r01.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.
-i, --indent
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={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.
-p, --packet
send an ATA IDENTIFY PACKET DEVICE command (via the SATL). The default action is to send an ATA IDENTIFY DEVICE command.
-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.
-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.
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"). Prior to lk 2.6.29 USB mass storage limited sense data to 18 bytes which made the --ck_cond
option yield strange (truncated) results.
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 (C) 2006-2013 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
POSE.
SEE ALSO
sg_vpd(sg3_utils), sg_inq(sg3_utils), sdparm(sdparm), hdparm(hdparm)
sg3_utils-1.37 June 2013 SG_SAT_IDENTIFY(8)