The number of times that the requested operation is to be
performed. By default, mt performs command once. Multiple
operations of command can be performed by specifying
count.
The following available commands that can be sent to a
magnetic tape drive are supported. Only as many characters as are required to
uniquely identify a
command need be specified.
asf
Specifies absolute space to count file number.
This is equivalent to a rewind followed by a fsf
count.
bsf
Back spaces over count EOF marks. The tape is
positioned on the beginning-of-tape side of the EOF mark.
bsr
Back spaces count records.
bssf
Back spaces over the requested number of sequential file
marks. Sequential file marks are where the file marks are one right after the
other with no other blocks of any kind between the file marks. The number
argument specifies how many sequential file marks to which to space. For
example,
bssf 4 searches backwards to the first place where there are 4
sequential file marks and positions to the BOP side of the 4th file mark.
This command is not supported by all drives.
eof
weof
Writes count EOF marks at the current position on
the tape.
fsf
Forward spaces over count EOF marks. The tape is
positioned on the first block of the file.
fsr
Forward spaces count records.
fssf
Forward spaces the over requested number of sequential
file marks. Sequential file marks are where the file marks are one right after
the other with no other blocks of any kind between the file marks. The number
argument specifies how many sequential file marks to which to space. For
example,
fssf 4 searches forwards to the first place where there are 4
sequential file marks and positions after the 4th file mark.
This command is not supported by all drives.
load
Requests drive load and thread current media. Not
supported by all drives.
lock
Prevents media removal.
nbsf
Back spaces count files. The tape is positioned on
the first block of the file. This is equivalent to count+1 bsfs
followed by one fsf.
seek
Positions to requested logical tape position.
tell
Gets and prints current logical tape position.
unlock
Allows media removal.
If count is specified with any of the following commands,
the count is ignored and the command is performed only once.
config
Reads the drives current configuration from the driver
and displays it in
st.conf format. See
st(4D) for definition of
fields and there meanings.
eom
Spaces to the end of recorded media on the tape. This is
useful for appending files onto previously written tapes.
erase
Erases the entire tape.
Some tape drives have option settings where only portions of the
tape can be erased. Be sure to select the correct setting to erase the whole
tape. Erasing a tape can take a long time depending on the device and/or
tape. Refer to the device specific manual for time details.
forcereserve
Attempts to break a SCSI II reserve issued by another
initiator. When this command completes, the drive is not reserved for the
current initiator, but is available for use. This command can be only be
executed by those with super-user privileges.
offline
rewoffl
Rewinds the tape and, if appropriate, takes the drive
unit off-line by unloading the tape.
release
Re-establishes the default behavior of releasing at
close.
reserve
Allows the tape drive to remain reserved after closing
the device. The drive must then be explicitly released.
retension
Rewinds the cartridge tape completely, then winds it
forward to the end of the reel and back to beginning-of-tape to smooth out
tape tension.
rewind
Rewinds the tape.
status
Prints status information about the tape unit.
Status information can include the sense key reported by the
drive, the residual and retries for the last operation, the current tape
position reported in file number, and the number of blocks from the
beginning of that file. It might also report that WORM media is loaded in
that drive.