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SG_SAT_SET_FEATURES(8)             SG3_UTILS            SG_SAT_SET_FEATURES(8)

NAME
       sg_sat_set_features - use ATA SET FEATURES command via a SCSI to ATA
       Translation (SAT) layer

SYNOPSIS
       sg_sat_set_features [--count=CO] [--ck_cond] [--extended]
       [--feature=FEA] [--help] [--lba=LBA] [--len={16|12}] [--readonly]
       [--verbose] [--version] DEVICE

DESCRIPTION
       This utility sends an ATA SET FEATURES command to the DEVICE.  This
       command is used to change settings of ATA non-packet (i.e. disks) and
       packet devices (e.g. cd/dvd drives). Rather than send the SET FEATURES
       command directly to the device it is 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 sat3r05b.pdf .

       The features can be read using the sg_sat_identify utility which uses
       either the ATA IDENTIFY DEVICE (for non-packet devices) or the IDENTIFY
       PACKET DEVICE (for packet devices) command.

OPTIONS
       Arguments to long options are mandatory for short options as well.

       -c, --count=CO
              the number CO is placed in the "count" field in the ATA SET
              FEATURES command. Only some subcommands (a term used for the
              value placed in the "feature" field) require the count field to
              be set.  The default value placed in the "count" field is 0.

       -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 ATA command succeeded or failed.
              When clear the SATL should only yield a sense buffer containing
              a ATA Result descriptor if the ATA command failed.

       -e, --extended
              allow for extended LBA numbers (i.e. larger than 32 bits).  This
              value is enabled automatically for large LBA numbers, but can be
              enabled explicitly even for low LBA numbers with this option.

       -f, --feature=FEA
              the value FEA is placed in the "feature" field in the ATA SET
              FEATURES command. The term "subcommand" is sometimes used for
              this value. The default value placed in the "feature" field is 0
              which is reserved and hence should not change anything. Two
              common examples are 2h to enable the write cache and 82h to
              disable it.

       -h, --help
              outputs the usage message summarizing command line options then
              exits. Ignores DEVICE if given.

       -L, --lba=LBA
              the number LBA is placed in the "lba" field of the ATA SET
              FEATURES command. Only some sub-commands (a term used for the
              value placed in the "feature" field) require the lba field to be
              set. This value is typically not a "logical block address" as
              the acronym might imply.  The default value placed in the "lba"
              field is 0. The maximum value allowed for LBA is 0xfffffffe (or
              0xffffff if --len=12).

       -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. Some SCSI transports cannot convey SCSI commands longer than
              12 bytes.

       -r, --readonly
              causes the DEVICE to be opened with the read-only flag (O_RDONLY
              in Unix). The default action is to open DEVICE with the
              read-write flag (O_RDWR in Unix). In some cases sending power
              management commands to ATA disks are defeated by OS actions on
              the close() if the DEVICE was opened with the read-write flag
              (e.g. the OS might think it needs to flush something to disk).

       -v, --verbose
              increases the level or verbosity.

       -V, --version
              print out version string

NOTES
       In the 2.4 series of Linux kernels the DEVICE must be a SCSI generic
       (sg) device. In the 2.6 and 3 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_set_features 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) 2007-2014 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO
       warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.

SEE ALSO
       sg_sat_identify(sg3_utils), sg_inq(sg3_utils), sdparm(sdparm),
       hdparm(hdparm)

sg3_utils-1.40                   November 2014          SG_SAT_SET_FEATURES(8)