linux - mt (1)
NAME
mt - control magnetic tape drive operation
SYNOPSIS
mt [-f device] operation [count]
DESCRIPTION
This manual page documents the tape control program mt.
mt performs the given operation, which must be one of the
tape operations listed below, on a tape drive. The path
of the tape device to operate on can be given with the -f
or -t option. If neither of those options is given, and
the environment variable TAPE is set, it is used. Other-
wise, a default device defined in the file
/usr/include/sys/mtio.h is used. The device must a char-
acter special file.
Some operations optionally take a repeat count, which can
be given after the operation name and defaults to 1.
The available operations are listed below. Unique abbre-
viations are accepted. Not all operations are available
on all systems, or work on all types of tape drives.
fsf Forward space count files. The tape is positioned
on the first block of the next file.
fsfm Forward space count files. The tape is positioned
on the last block of the previous file.
bsf Backward space count files. The tape is positioned
on the last block of the previous file.
bsfm 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.
fss (SCSI tapes) Forward space count setmarks.
bss (SCSI tapes) Backward space count setmarks.
weof Write count EOF marks at current position.
wset (SCSI tapes) Write count setmarks at current posi-
tion (only SCSI tape).
rewind Rewind the tape.
offline, rewoffl
status Print status information about the tape unit.
retension
Rewind the tape, then wind it to the end of the
reel, then rewind it again.
eod, seod
Space to end of valid data. Used on streamer tape
drives to append data to the logical and of tape.
erase Erase the 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 num-
ber. The proper value for unbuffered operation is
zero and "normal" buffered operation one. The mean-
ings of other values can be found in the drive doc-
umentation 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 com-
piled 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 operation 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 den-
sity codes to standard output.
datcompression
(some SCSI-2 DAT tapes) Inquire or set the compres-
sion status (on/off). If the count is omitted the
compression status is printed. If the count is
zero, compression is disabled. If the count is
nonzero, compression is enabled. The command uses
the SCSI ioctl to read and write the Data Compres-
sion Characteristics mode page (15). ONLY ROOT CAN
USE THIS COMMAND.
mt exits with a status of 0 if the operation succeeded, 1
if the operation or device name given was invalid, or 2 if
the operation failed.