mt - control magnetic tape drive operation
mt [-h] [-f device] operation [count] [arguments...]
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 commands can
also be listed by running the program with the -h option. The version of mt is printed
with the -v or --version option. The path of the tape device on which to operate 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. Otherwise, a default device defined in the file
/usr/include/sys/mtio.h is used.
Some operations optionally take an argument or repeat count, which can be given after the
operation name and defaults to 1. The postfix k , M , or G can be used to give counts in
units of 1024, 1024 * 1024, or 1024 * 1024 * 1024, respectively.
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.
fsf Forward space count files. The tape is positioned on the first block of the next
fsfm Forward space past count file marks, then backward space one file record. This
leaves the tape positioned on the last block of the file that is count-1 files past
the current file.
bsf Backward space count files. The tape is positioned on the last block of the previ-
bsfm Backward space past count file marks, then forward space one file record. This
leaves the tape positioned on the first block of the file that is count-1 files
before the current file.
asf The tape is positioned at the beginning of the count file. Positioning is done by
first rewinding the tape and then spacing forward over count filemarks.
fsr Forward space count records.
bsr Backward space count records.
fss (SCSI tapes) Forward space count setmarks.
bss (SCSI tapes) Backward space count setmarks.
Space to end of valid data. Used on streamer tape drives to append data to the
logical end of tape.
rewind Rewind the tape.
offline, rewoffl, eject
Rewind the tape and, if applicable, unload the tape.
Rewind the tape, then wind it to the end of the reel, then rewind it again.
Write count EOF marks at current position.
wset (SCSI tapes) Write count setmarks at current position (only SCSI tape).
erase Erase the tape.
status Print status information about the tape unit. (If the density code is "no transla-
tion" in the status output, this does not affect working of the tape drive.)
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. The block address
should be obtained from a tell call earlier.
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.
(SCSI tapes) Switch to the partition determined by count. The default data parti-
tion of the tape is numbered zero. Switching partition is available only if enabled
for the device, the device supports multiple partitions, and the tape is formatted
with multiple partitions.
(SCSI tapes) The tape position is set to block count in the partition given by the
argument after count. The default partition is zero.
(SCSI tapes) Format the tape with one (count is zero) or two partitions (count
gives the size of the second partition in megabytes). The tape drive must be able
to format partitioned tapes with initiator-specified partition size and partition
support must be enabled for the drive.
load (SCSI tapes) Send the load command to the tape drive. The drives usually load the
tape when a new cartridge is inserted. The argument count can usually be omitted.
Some HP changers load tape n if the count 10000 + n is given (a special funtion in
the Linux st driver).
lock (SCSI tapes) Lock the tape drive door.
unlock (SCSI tapes) Unlock the tape drive door.
setblk (SCSI tapes) Set the block size of the drive to count bytes per record.
(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.
(SCSI tapes) Write explanation of some common density codes to standard output.
(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 the case of a SCSI-2
drive, from the SCSI-2 standard.
(SCSI tapes) The compression within the drive can be switched on or off using the
MTCOMPRESSION ioctl. Note that this method is not supported by all drives imple-
menting compression. For instance, the Exabyte 8 mm drives use density codes to
(SCSI tapes) Set the driver options bits for the device to the defined values.
Allowed only for the superuser. The bits can be set either by ORing the option bits
from the file /usr/include/linux/mtio.h to count, or by using the following key-
words (as many keywords can be used on the same line as necessary, unambiguous
buffer-writes buffered writes enabled
async-writes asynchronous writes enabled
read-ahead read-ahead for fixed block size
debug debugging (if compiled into driver)
two-fms write two filemarks when file closed
fast-eod space directly to eod (and lose file number)
no-wait don't wait until rewind, etc. complete
auto-lock automatically lock/unlock drive door
def-writes the block size and density are for writes
can-bsr drive can space backwards as well
no-blklimits drive doesn't support read block limits
can-partitions drive can handle partitioned tapes
scsi2logical seek and tell use SCSI-2 logical block addresses instead of device
sili Set the SILI bit is when reading in variable block mode. This may
speed up reading blocks shorter than the read byte count. Set this
option only if you know that the drive supports SILI and the HBA
reliably returns transfer residual byte counts. Requires kernel ver-
sion >= 2.6.26.
sysv enable the System V semantics
(SCSI tapes) Set selected driver options bits. The methods to specify the bits to
set are given above in the description of stoptions. Allowed only for the supe-
(SCSI tapes) Clear selected driver option bits. The methods to specify the bits to
clear are given above in description of stoptions. Allowed only for the superuser.
(SCSI tapes) Print the currently enabled options for the device. Requires kernel
version >= 2.6.26 and sysfs must be mounted at /sys.
(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. Allowed only for the
(SCSI tapes) Set the default block size of the device to count bytes. The value -1
disables the default block size. The block size set by setblk overrides the
default until a new tape is inserted. Allowed only for the superuser.
(SCSI tapes) Set the default density code. The value -1 disables the default den-
sity. The density set by setdensity overrides the default until a new tape is
inserted. Allowed only for the superuser.
(SCSI tapes) Set the default drive buffer code. The value -1 disables the default
drive buffer code. The drive buffer code set by drvbuffer overrides the default
until a new tape is inserted. Allowed only for the superuser.
(SCSI tapes) Set the default compression state. The value -1 disables the default
compression. The compression state set by compression overrides the default until a
new tape is inserted. Allowed only for the superuser.
sets the normal timeout for the device. The value is given in seconds. Allowed only
for the superuser.
sets the long timeout for the device. The value is given in seconds. Allowed only
for the superuser.
set the cleaning request interpretation parameters.
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.
The program is written by Kai Makisara <Kai.Makisara@kolumbus.fi>.
The program and the manual page are copyrighted by Kai Makisara, 1998-2008. They can be
distributed according to the GNU Copyleft.
April 2008 MT(1)