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 default 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  cartridges  or  cd/dvd  media typically implement this command.  The
       definition 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 '--prevent=2'.  Cannot be used with
              --prevent=PC option  (i.e.  either  use  no  options  (hence  prevent  removal),  this  option  or
              --prevent=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 removal 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 © 2004-2012 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_start(sg3_utils), sg_persist(sg3_utils)

sg3_utils-1.35                                    November 2012                                    SG_PREVENT(8)