---
name: "mt"
section: "1"
platform: "linux"
package: "cpio"
version: "2.4.2-32"
release: "Debian 2.2 (Potato)"
platforms: ["linux", "freebsd", "openbsd"]
url: "https://new.carta.tech/mt"
---

# mt(1)

control magnetic tape drive operation

## NAME

mt - control magnetic tape drive operation

## SYNOPSIS

**mt** \[-V\] \[-f device\] \[--file=device\] \[--rsh-command=command\] \[--version\] operation \[count\]

## DESCRIPTION

This manual page documents the GNU version of **mt**. **mt** performs the given *operation*, which must be one of the tape operations listed below, on a tape drive.

The default tape device to operate on is taken from the file */usr/include/sys/mtio.h* when **mt** is compiled.  It can be overridden by giving a device file name in the environment variable **TAPE** or by a command line option (see below), which also overrides the environment variable.

The device must be either a character special file or a remote tape drive.  To use a tape drive on another machine as the archive, use a filename that starts with \`HOSTNAME:'.  The hostname can be preceded by a username and an \`@' to access the remote tape drive as that user, if you have permission to do so (typically an entry in that user's \`~/.rhosts' file).

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. Some operations optionally take a repeat count, which can be given after the operation name and defaults to 1.

- eof, weof

  Write *count* EOF marks at current position.

- fsf

  Forward space *count* files. The tape is positioned on the first block of the next file.

- bsf

  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.

- bsfm

  Backward space *count* file marks. The tape is positioned on the beginning-of-the-tape side of the file mark.

- fsfm

  Forward space *count* file marks. The tape is positioned on the beginning-of-the-tape side of the file mark.

- asf

  Absolute space to file number *count*. Equivalent to rewind followed by fsf *count*.

- eom

  Space to the end of the recorded media on the tape (for appending files onto tapes).

- 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.

- erase

  Erase the tape.

- fss

  (SCSI tapes) Forward space *count* setmarks.

- bss

  (SCSI tapes) Backward space *count* setmarks.

- wset

  (SCSI tapes) Write *count* setmarks at current position (only SCSI tape).

- eod, seod

  Space to end of valid data.  Used on streamer tape drives to append data to the logical and of 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 one the compression status is printed. If the *count* is zero, compression is disabled. Otherwise, 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.

### OPTIONS

- *-f, --file=device*

  Use *device* as the file name of the tape drive to operate on. To use a tape drive on another machine, use a filename that starts with \`HOSTNAME:'.  The hostname can be preceded by a username and an \`@' to access the remote tape drive as that user, if you have permission to do so (typically an entry in that user's \`~/.rhosts' file).

- *--rsh-command=command*

  Notifies **mt** that it should use *command* to communicate with remote devices instead of */usr/bin/ssh* or */usr/bin/rsh*.

- *-V, --version*

  Print the version number of **mt**.