SG_SAT_SET_FEATURES(8)						     SG3_UTILS						    SG_SAT_SET_FEATURES(8)

NAME

       sg_sat_set_featutes - sends a ATA SET FEATURES command via a SCSI to ATA Translation (SAT) layer

SYNOPSIS

       sg_sat_set_features [--count=CO] [--chk_cond] [--feature=FEA] [--help] [--len=16|12] [--lba=LBA] [--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 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 the 16 byte cdb variant.

       The SATL may be in an operating system driver, in host bus adapter firmware or in some external enclosure.

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

       -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 exam-
	      ples 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, --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.

       -L, --lba=LBA
	      the number LBA is placed in the "lba" field in the ATA SET FEATURES command. Only some subcommands (a term used for the value placed
	      in  the  "feature"  field) require the lba field to be set.  This value is not a "logical block address" as the acronym might imply.
	      The default value placed in the "lba" field is 0.

       -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 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").

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 Doug Gilbert

REPORTING BUGS

       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT

       Copyright (C) 2007 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A  PARTICULAR  PUR-
       POSE.

SEE ALSO

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

sg3_utils-1.25							    August 2007 					    SG_SAT_SET_FEATURES(8)