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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 Trans-
     lation (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 de-
     vices (e.g. cd/dvd drives). Rather than send the SET FEATURES  command  di-
     rectly  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  ei-
     ther  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 en-
	    abled 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  FEA-
	    TURES  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 ex-
	    its. 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. Other-
     wise 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 BSD-2-Clause license. There is NO war-
     ranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO
     sg_sat_identify(sg3_utils), sg_inq(sg3_utils),  sdparm(sdparm),  hdparm(hd-
     parm)

sg3_utils-1.40			  November 2014 	  SG_SAT_SET_FEATURES(8)

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