| .TH SG_PREVENT "8" "November 2012" "sg3_utils\-1.35" SG3_UTILS |
| .SH NAME |
| sg_prevent \- send SCSI PREVENT ALLOW MEDIUM REMOVAL command |
| .SH SYNOPSIS |
| .B sg_prevent |
| [\fI\-\-allow\fR] [\fI\-\-help\fR] [\fI\-\-prevent=PC\fR] |
| [\fI\-\-verbose\fR] [\fI\-\-version\fR] \fIDEVICE\fR |
| .SH DESCRIPTION |
| .\" Add any additional description here |
| .PP |
| Sends a SCSI PREVENT ALLOW MEDIUM REMOVAL command to \fIDEVICE\fR. |
| 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. |
| .SH OPTIONS |
| Arguments to long options are mandatory for short options as well. |
| .TP |
| \fB\-a\fR, \fB\-\-allow\fR |
| allow medium removal. This is equivalent to setting to '\-\-prevent=2'. |
| Cannot be used with \fI\-\-prevent=PC\fR option (i.e. either use |
| no options (hence prevent removal), this option or \fI\-\-prevent=PC\fR). |
| .TP |
| \fB\-h\fR, \fB\-\-help\fR |
| output the usage message then exit. |
| .TP |
| \fB\-p\fR, \fB\-\-prevent\fR=\fIPC\fR |
| where \fIPC\fR 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). |
| .TP |
| \fB\-v\fR, \fB\-\-verbose\fR |
| increase the level of verbosity, (i.e. debug output). |
| .TP |
| \fB\-V\fR, \fB\-\-version\fR |
| print the version string and then exit. |
| .SH EXIT STATUS |
| The exit status of sg_prevent is 0 when it is successful. Otherwise see |
| the sg3_utils(8) man page. |
| .SH AUTHORS |
| Written by Douglas Gilbert. |
| .SH "REPORTING BUGS" |
| Report bugs to <dgilbert at interlog dot com>. |
| .SH COPYRIGHT |
| Copyright \(co 2004\-2012 Douglas Gilbert |
| .br |
| This software is distributed under a BSD\-2\-Clause license. There is NO |
| warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| .SH "SEE ALSO" |
| .B sg_start(sg3_utils), sg_persist(sg3_utils) |
