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)