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 --prevent=PC).
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 SPC-3).
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.