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 © 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)
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