mt(1) —

NAME

mt − magnetic tape utility

SYNOPSIS

mt [−v] [−b tape_blk_factor] [−f tapename] command

DESCRIPTION

The mt program provides generic front-end tape drive support. This command supports QIC-02, SCSI bus interfaces, and floppy interface tape drives.

The ways in which this command is used can be separated into three groups. The three groups are explained below; users can also access on-line usage instructions by typing mt:

1. Common tape commands
These are the common commands that apply to any type of tape drive:

eraseerase entire tape
rewindrewind the tape
retensionwind the tape to end of reel and rewind it

2. Floppy tape-specific commands
These are the commands that apply to floppy tape drives only:

formatformat tape
getinfodrive configuration information

3. Other tape commands
These are the commands that apply to non-floppy tape drives, which include QIC-02 or SCSI bus interface tape drives:

wfmwrite file mark
sfmseek next file mark
enddataseek to end of data (SCSI drives only)

End of data corresponds to a point on the tape just past where the last data (or file mark) was written.

The −v option will provide output on the type of device found and print the status of the requested command.

The −b option allows users to select a different tape block size if both the tape drive and the installed tape support variable-length block size. tape_blk_factor is a factor of 512 bytes. To set /dev/tape to 1024 bytes/block, type

mt −v −b 2 −f /dev/tape

This option is useful when the tape drive that supports variable-length block size cannot determine the block size of a previously recorded tape. Using the new −b option, the user can select a different block size. Tape drives that can determine the block size of a previously recorded tape (for example, Wangtek 5525es or Tandberg Data 3822 SCSI interface streaming 1/4-inch cartridge tape drive) do not need to use the −b option unless the user wants to write to tape with a different block size length. The −b option would be used, for example, if a tape must be written in a specific blocking factor for portability. The −b option is supported only on the following SCSI controllers:

Adaptec 1520, 1540, 1740
Bustek 742
DPT20xx
IBM PS2 MCA
NCR 53C700
Olivetti ESC-X
WD7000ex, WD7000asc

The −f option allows the user to specify the name of the tape device. The default tape device is /dev/tape.

NOTES

Note that some QIC-02 devices do not respond to some commands. For example, the Gigatrend DAT tape does not appear to do anything when given the retension command.

Note also that some devices take a long time to execute certain commands. For example, the Exabyte 8200 DAT tape sometimes takes approximately 90 minutes to rewind.

ADDED VALUE

This entry, supplied by SunSoft, Inc., is an extension of UNIX System V.