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SG_PREVENT(8)			   SG3_UTILS			 SG_PREVENT(8)

NAME
       sg_prevent - send SCSI PREVENT ALLOW MEDIUM REMOVAL command

SYNOPSIS
       sg_prevent  [--allow]  [--help]	[--prevent=PC] [--verbose] [--version]
       DEVICE

DESCRIPTION
       Sends a SCSI PREVENT ALLOW MEDIUM REMOVAL command to DEVICE.   The  de-
       fault  action of	this utility is	to prevent the removing	or ejecting of
       the medium from a drive.	This is	done by	ignoring the SCSI  START  STOP
       UNIT  command (see sg_start) and	ignoring the eject button on the drive
       when the	user presses it. Drives	that hold removable disks,  tape  car-
       tridges	or cd/dvd media	typically implement this command.  The defini-
       tion of the "prevent" codes for this command differ between  disks  and
       tapes  (covered	by  SBC-3  and	SSC-3)	and  cd/dvd drives (covered by
       MMC-5). The "prevent codes" described here are from MMC-5.

OPTIONS
       Arguments to long options are mandatory for short options as well.

       -a, --allow
	      allow medium removal. This is equivalent to setting  to  '--pre-
	      vent=2'.	 Cannot	 be used with --prevent=PC option (i.e.	either
	      use no options (hence prevent removal), this  option  or	--pre-
	      vent=PC).

       -h, --help
	      output the usage message then exit.

       -p, --prevent=PC
	      where  PC	 is a prevent code value. Defined values are: 0	allows
	      removal, 1 prevents removal (default), 2 allows  persistent  re-
	      moval  while 3 prevents persistent removal. "Persistent" in this
	      context means that the initiator (port) that  successfully  uses
	      code  3 blocks other initiators (ports) from allowing removal. A
	      "persistent prevent" state can be	cleared	by the owner  allowing
	      persistent  removal  (code 2) or a power cycle (or anything that
	      resets the device	(LU)) or some special commands	(e.g.  various
	      service actions of Persistent Reserve Out, see SPC-3).

       -v, --verbose
	      increase the level of verbosity, (i.e. debug output).

       -V, --version
	      print the	version	string and then	exit.

EXIT STATUS
       The exit	status of sg_prevent is	0 when it is successful. Otherwise see
       the sg3_utils(8)	man page.

AUTHORS
       Written by Douglas Gilbert.

REPORTING BUGS
       Report bugs to <dgilbert	at interlog dot	com>.

COPYRIGHT
       Copyright (C) 2004-2012 Douglas Gilbert
       This software is	distributed under a FreeBSD license. There is NO  war-
       ranty;  not  even  for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
       POSE.

SEE ALSO
       sg_start(sg3_utils), sg_persist(sg3_utils)

sg3_utils-1.35			 November 2012			 SG_PREVENT(8)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | AUTHORS | REPORTING BUGS | COPYRIGHT | SEE ALSO

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