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 © 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)