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. Otherwise, a default device defined in the file /usr/include/sys/mtio.h is used. The device must a character 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 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.

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 position (only SCSI tape).

rewind
    Rewind the tape.

offline, rewoffl
    Rewind the tape and, if applicable, unload the tape.

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 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 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 density codes to standard output.

datcompression
    (some SCSI-2 DAT tapes) Inquire or set the compression 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 Compression 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.