Provided by: sg3-utils_1.17-2_i386
sg_requests - send the scsi command request sense
sg_requests [--desc] [--help] [--verbose] [--version] <scsi_device>
Send REQUEST SENSE command to a Linux SCSI device and output the
response which is expected to be in sense data format. Both fixed and
descriptor format are supported.
--desc | -d
sets the ’DESC’ bit in the REQUEST SENSE SCSI command. The given
device should return sense data in descriptor (rather than
fixed) format. This will only occur if the given device
recognizes descriptor format (SPC-3 and later). If the device is
pre SPC-3 then setting a bit in a reserved field may cause a
check condition status with an illegal request sense key.
--help | -h
output the usage message then exit.
--verbose | -v
increase the level of verbosity, (i.e. debug output).
Additionally the response (if received) is output in ASCII-HEX.
Use this option multiple times for greater verbosity.
--version | -V
print the version string and then exit.
In SCSI 1 and 2 the REQUEST SENSE command was very important for error
and warning processing in SCSI. The autosense capability rendered this
command almost superfluous.
However recent SCSI drafts (e.g. SPC rev 23 and SBC-2 rev 16) increase
the utility of the REQUEST SENSE command. Idle and standby power
conditions can now be detected with this command; a progress indication
is given during FORMAT (when that command was started with with IMMED=1
in its parameter header); and the Filemark, ILI and EOM bits may be set
(e.g. by a tape drive). Interestingly the sense key is set to "no
sense" while the asc/ascq code convey the information (e.g. 0x5e/0x4
"Standby condition activated by command").
The REQUEST SENSE command is not marked as mandatory in SPC-3 (i.e. for
all SCSI devices) but is marked as mandatory in SBC-2 (i.e. for disks),
SSC-3 (i.e. for tapes) and MMC-4 (i.e. for CD/DVD drives).
Written by Douglas Gilbert.
Report bugs to <dgilbert at interlog dot com>.
Copyright © 2004-2005 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR