NAME¶
mt - control magnetic tape drive operation
SYNOPSIS¶
mt [-h] [-f device] operation [count] [arguments...]
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 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 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.
- 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.
- eod, seod
- 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.
- retension
- Rewind the tape, then wind it to the end of the reel, then
rewind it again.
- weof, eof
- 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 translation" 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.
- setpartition
- (SCSI tapes) Switch to the partition determined by
count. The default data partition 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.
- partseek
- (SCSI tapes) The tape position is set to block count
in the partition given by the argument after count. The default partition
is zero.
- mkpartition
- (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.
- 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.
- densities
- (SCSI tapes) Write explanation of some common density codes
to standard output.
- 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 the case of a SCSI-2 drive,
from the SCSI-2 standard.
- compression
- (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 implementing compression. For instance, the
Exabyte 8 mm drives use density codes to select compression.
- stoptions
- (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 keywords (as many keywords can be
used on the same line as necessary, unambiguous abbreviations
allowed):
- 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 dependent addresses
- 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 version
>= 2.6.26.
- sysv
- enable the System V semantics
- stsetoptions
- (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 superuser.
- stclearoptions
- (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.
- stshowoptions
- (SCSI tapes) Print the currently enabled options for the
device. Requires kernel version >= 2.6.26 and sysfs must be mounted at
/sys.
- 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. Allowed only for the superuser.
- defblksize
- (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.
- defdensity
- (SCSI tapes) Set the default density code. The value -1
disables the default density. The density set by setdensity
overrides the default until a new tape is inserted. Allowed only for the
superuser.
- defdrvbuffer
- (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.
- defcompression
- (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.
- sttimeout
- sets the normal timeout for the device. The value is given
in seconds. Allowed only for the superuser.
- stlongtimeout
- sets the long timeout for the device. The value is given in
seconds. Allowed only for the superuser.
- stsetcln
- 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.
AUTHOR¶
The program is written by Kai Makisara <Kai.Makisara@kolumbus.fi>.
COPYRIGHT¶
The program and the manual page are copyrighted by Kai Makisara, 1998-2008. They
can be distributed according to the GNU Copyleft.
SEE ALSO¶
st(4)