sg_prevent(8)

1SG_PREVENT(8)                      SG3_UTILS                     SG_PREVENT(8)
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NAME

6       sg_prevent - sends a SCSI PREVENT ALLOW MEDIUM REMOVAL command
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SYNOPSIS

9       sg_prevent  [--allow]  [--help]  [--prevent=PC] [--verbose] [--version]
10       DEVICE
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DESCRIPTION

13       Sends a SCSI PREVENT ALLOW  MEDIUM  REMOVAL  command  to  DEVICE.   The
14       default  action  of this utility is to prevent the removing or ejecting
15       of the medium from a drive. This is done by  ignoring  the  SCSI  START
16       STOP  UNIT  command (see sg_start) and ignoring the eject button on the
17       drive when the user presses it. Drives that hold removable disks,  tape
18       cartridges or cd/dvd media typically implement this command.  The defi‐
19       nition of the "prevent" codes for this command differ between disks and
20       tapes  (covered  by  SBC-3  and  SSC-3)  and  cd/dvd drives (covered by
21       MMC-5). The "prevent codes" described here are from MMC-5.
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OPTIONS

24       Arguments to long options are mandatory for short options as well.
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26       -a, --allow
27              allow medium removal. This is equivalent to setting  to  '--pre‐
28              vent=2'.   Cannot  be used with --prevent=PC option (i.e. either
29              use no options (hence prevent removal), this  option  or  --pre‐
30              vent=PC).
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32       -h, --help
33              output the usage message then exit.
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35       -p, --prevent=PC
36              where  PC  is a prevent code value. Defined values are: 0 allows
37              removal, 1  prevents  removal  (default),  2  allows  persistent
38              removal  while  3  prevents  persistent removal. "Persistent" in
39              this context means that the initiator (port)  that  successfully
40              uses  code  3  blocks  other  initiators  (ports)  from allowing
41              removal. A "persistent prevent" state  can  be  cleared  by  the
42              owner  allowing persistent removal (code 2) or a power cycle (or
43              anything that resets the device (lun)) or some special  commands
44              (e.g.  various  service  actions  of Persistent Reserve Out, see
45              SPC-3).
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47       -v, --verbose
48              increase the level of verbosity, (i.e. debug output).
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50       -V, --version
51              print the version string and then exit.
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EXIT STATUS

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

58       Written by Douglas Gilbert.
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REPORTING BUGS

61       Report bugs to <dgilbert at interlog dot com>.
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COPYRIGHT

64       Copyright © 2004-2007 Douglas Gilbert
65       This  software is distributed under a FreeBSD license. There is NO war‐
66       ranty; not even for MERCHANTABILITY or FITNESS FOR  A  PARTICULAR  PUR‐
67       POSE.
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