man > SG_SAT_SET_FEATURES(8)

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 oper‐
       ating 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  de‐
              scriptor  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 au‐
              tomatically for large LBA numbers, but can be enabled explicitly even for low LBA num‐
              bers 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  com‐
              mon 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 al‐
              lowed 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  argu‐
              ment  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 MER‐
       CHANTABILITY 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)