mt(1): control magnetic tape drive operation

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 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 previous file.

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.

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
sysv: enable the System V semantics

stsetoptions