mt

Control magnetic tape drive operations

TLDR

Check status of a tape drive

$ mt -f [/dev/nst0] status

Rewind tape to beginning

$ mt -f [/dev/nst0] rewind

Forward space a number of files

$ mt -f [/dev/nst0] fsf [count]

Rewind and position at beginning of specified file

$ mt -f [/dev/nst0] asf [count]

Position tape at end of data

$ mt -f [/dev/nst0] eod

Rewind and eject tape

$ mt -f [/dev/nst0] eject

Write EOF mark at current position

$ mt -f [/dev/nst0] eof

mt controls magnetic tape drive operations, commonly used with LTO (Linear Tape-Open) and other SCSI tape drives. It provides commands for positioning, rewinding, ejecting, and writing control marks on tape media.The device is specified with -f option or via the TAPE environment variable. Use /dev/nstX for non-rewinding devices (preserves position after operations) or /dev/stX for auto-rewinding devices.

PARAMETERS

-f _device_, -t _device_

Specify tape device (e.g., /dev/nst0, /dev/st0)

-h

List available commands

-V, --version

Display version information

OPERATIONS

status

Print tape drive status and position

rewind

Rewind tape to beginning

fsf _count_

Forward space specified number of files

bsf _count_

Backward space specified number of files

fsr _count_

Forward space specified number of records

bsr _count_

Backward space specified number of records

asf _count_

Rewind and position at beginning of specified file

eod, seod

Space to end of valid data

weof _count_, eof

Write EOF (end-of-file) marks

eject, offline, rewoffl

Rewind and unload/eject tape

erase

Erase entire tape (long operation)

retension

Rewind, wind to end, rewind again (conditions tape)

setblk _size_

Set hardware block size in bytes (0 for variable)

seek _block_

Seek to specified block number (SCSI)

tell

Print current block number (SCSI)

INSTALL

sudo dnf install mt-st

sudo apk add mt-st

sudo zypper install mt-st

nix profile install nixpkgs#mt-st

CAVEATS

Tape operations can be slow, especially erase and retension. Using the wrong device (st vs nst) can cause unexpected tape rewinding. Some operations are SCSI-specific. Ensure correct device permissions for non-root access.

HISTORY

mt (magnetic tape) has been a standard Unix utility since early Unix systems for controlling tape drives. The Linux version supports additional SCSI tape features beyond traditional operations.

mt