MT(1L)MT(1L)NAMEmt - control magnetic tape drive operation
SYNOPSISmt [-V] [-f device] [--file=device] [--version] operation [count]
DESCRIPTION
This manual page documents the GNU version of mt. mt performs the
given operation, which must be one of the tape operations listed below,
on a tape drive.
The default tape device to operate on is taken from the file
/usr/include/sys/mtio.h when mt is compiled. It can be overridden by
giving a device file name in the environment variable TAPE or by a com‐
mand line option (see below), which also overrides the environment
variable.
The device must be either a character special file or a remote tape
drive. To use a tape drive on another machine as the archive, use a
filename that starts with `HOSTNAME:'. The hostname can be preceded by
a username and an `@' to access the remote tape drive as that user, if
you have permission to do so (typically an entry in that user's
`~/.rhosts' file).
The available operations are listed below. Unique abbreviations are
accepted. Not all operations are available on all systems, or work on
all types of tape drives. Some operations optionally take a repeat
count, which can be given after the operation name and defaults to 1.
eof, weof
Write count EOF marks at current position.
fsf Forward space count files. The tape is positioned on the first
block of the next file.
bsf Backward space count files. The tape is positioned on the first
block of the next file.
fsr Forward space count records.
bsr Backward space count records.
bsfm Backward space count file marks. The tape is positioned on the
beginning-of-the-tape side of the file mark.
fsfm Forward space count file marks. The tape is positioned on the
beginning-of-the-tape side of the file mark.
asf Absolute space to file number count. Equivalent to rewind fol‐
lowed by fsf count.
eom Space to the end of the recorded media on the tape (for append‐
ing files onto tapes).
rewind Rewind the tape.
offline, rewoffl
Rewind the tape and, if applicable, unload the tape.
status Print status information about the tape unit. `status 2' and
`status 3' print more information.
retension
Rewind the tape, then wind it to the end of the reel, then
rewind it again.
erase Erase the tape.
fss (SCSI tapes) Forward space count setmarks.
bss (SCSI tapes) Backward space count setmarks.
wset (SCSI tapes) Write count setmarks at current position (only SCSI
tape).
eod, seod
Space to end of valid data. Used on streamer tape drives to
append data to the logical and of tape.
setblk (SCSI tapes) Set the block size of the drive to count bytes per
record.
setdensity
(SCSI tapes) Set the tape density code to count. The proper
codes to use with each drive should be looked up from the drive
documentation.
drvbuffer
(SCSI tapes) Set the tape drive buffer code to number. The
proper value for unbuffered operation is zero and "normal"
buffered operation one. The meanings of other values can be
found in the drive documentation or, in case of a SCSI-2 drive,
from the SCSI-2 standard.
stoptions
(SCSI tapes) Set the driver options bits to count for the
device. The bits can be set by oring the following values: 1 to
enable write buffering, 2 to enable asynchronous writes, 4 to
enable read ahead, 8 to enable debugging output (if it has been
compiled to the driver).
stwrthreshold
(SCSI tapes) The write threshold for the tape device is set to
count kilobytes. The value must be smaller than or equal to the
driver buffer size.
seek (SCSI tapes) Seek to the count block on the tape. This opera‐
tion is available on some Tandberg and Wangtek streamers and
some SCSI-2 tape drives.
tell (SCSI tapes) Tell the current block on tape. This operation is
available on some Tandberg and Wangtek streamers and some SCSI-2
tape drives.
densities
(SCSI tapes) Write explanation of some common density codes to
standard output.
compression, datcompression
(some SCSI-2 DAT tapes) Inquire or set the compression status
(on/off). If the count is one the compression status is printed.
If the count is zero, compression is disabled. Otherwise, com‐
pression is enabled. The command uses the SCSI ioctl to read and
write the Data Compression Characteristics mode page (15). ONLY
ROOT CAN USE THIS COMMAND.
setpart, setpartition
Change active partition on tape drives supporting them. A count
of 0 means to position the tape in the default partition.
partseek
The tape position is set to block count in the partition given
by the argument after count. The default partition is 0.
mkpart, mkpartition
Creates tape partitions on tape drives supporting them. Creates
one partition if count is 0, two partitions otherwise. For
drives supporting initiator partitions, count is the size of the
second partition in megabytes. For drives only supporting
select or fixed partitions, count just specifies if one (count =
0) or two (count > 0) partitions are created.
mt exits with a status of 0 if the operation succeeded, 1 if the opera‐
tion or device name given was invalid, or 2 if the operation failed.
OPTIONS
-f, --file=device
Use device as the file name of the tape drive to operate on. To
use a tape drive on another machine, use a filename that starts
with `HOSTNAME:'. The hostname can be preceded by a username
and an `@' to access the remote tape drive as that user, if you
have permission to do so (typically an entry in that user's
`~/.rhosts' file).
-V, --version
Print the version number of mt.
MT(1L)
