sg_prevent - sends a SCSI PREVENT ALLOW MEDIUM REMOVAL command
sg_prevent [--allow] [--help] [--prevent=PC] [--verbose] [--version]
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.
Arguments to long options are mandatory for short options as well.
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
output the usage message then exit.
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 (lun)) or some special commands
(e.g. various service actions of Persistent Reserve Out, see
increase the level of verbosity, (i.e. debug output).
print the version string and then exit.
The exit status of sg_prevent is 0 when it is successful. Otherwise see
the sg3_utils(8) man page.
Written by Douglas Gilbert.
Report bugs to <dgilbert at interlog dot com>.
Copyright © 2004-2007 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR