Ubuntu Manpage: mt - control magnetic tape drive operation

NAME

       mt - control magnetic tape drive operation

SYNOPSIS

       mt [-h] [-f device] operation [count] [arguments...]

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 commands can also be listed by running the
program with the -h option.

Some operations optionally take an argument or repeat count, which can be given after the operation name
and defaults to 1. The postfix k , M , or G can be used to give counts in units of 1024, 1024 * 1024, or
1024 * 1024 * 1024, respectively.

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, then backward space one record. This leaves the tape positioned at the
last block of the file that is count - 1 files past the current file.

bsf Backward space count files. The tape is positioned on the last block of the previous file.

bsfm Backward space count files, then forward space one record. This leaves the tape positioned at the
first block of the file that is count - 1 files before the current file.

asf The tape is positioned at the beginning of the count file. Positioning is done by first rewinding
the tape and then spacing forward over count filemarks.

fsr Forward space count records.

bsr Backward space count records.

fss (SCSI tapes) Forward space count setmarks.

bss (SCSI tapes) Backward space count setmarks.

eod, seod
Space to end of valid data. Used on streamer tape drives to append data to the logical end of
tape.

rewind Rewind the tape.

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

retension
Rewind the tape, then wind it to the end of the reel, then rewind it again.

weof, eof
Write count EOF marks at current position.

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

erase Erase the tape. Note that this is a long erase, which on modern (high-capacity) tapes can take
many hours, and which usually can't be aborted.

status Print status information about the tape unit. (If the density code is "no translation" in the
status output, this does not affect working of the tape drive.)

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. The block address should be obtained from a
tell call earlier.

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.

setpartition
(SCSI tapes) Switch to the partition determined by count. The default data partition of the tape
is numbered zero. Switching partition is available only if enabled for the device, the device
supports multiple partitions, and the tape is formatted with multiple partitions.

partseek
(SCSI tapes) The tape position is set to block count in the partition given by the argument after
count. The default partition is zero.

mkpartition
(SCSI tapes) Format the tape with one (count is zero) or two partitions (count gives the size of
the second partition in megabytes). If the count is positive, it specifies the size of partition
1. From kernel version 4.6, if the count is negative, it specifies the size of partition 0. With
older kernels, a negative argument formats the tape with one partition. The tape drive must be
able to format partitioned tapes with initiator-specified partition size and partition support
must be enabled for the drive.

load (SCSI tapes) Send the load command to the tape drive. The drives usually load the tape when a new
cartridge is inserted. The argument count can usually be omitted. Some HP changers load tape n if
the count 10000 + n is given (a special function in the Linux st driver).

lock (SCSI tapes) Lock the tape drive door.

unlock (SCSI tapes) Unlock the tape drive door.

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.

densities
(SCSI tapes) Write explanation of some common density codes to standard output.

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 the case of a SCSI-2 drive, from the SCSI-2 standard.

compression
(SCSI tapes) The compression within the drive can be switched on or off using the MTCOMPRESSION
ioctl. Note that this method is not supported by all drives implementing compression. For
instance, the Exabyte 8 mm drives use density codes to select compression.

stoptions
(SCSI tapes) Set the driver options bits for the device to the defined values. Allowed only for
the superuser. The bits can be set either by ORing the option bits from the file
/usr/include/linux/mtio.h to count, or by using the following keywords (as many keywords can be
used on the same line as necessary, unambiguous abbreviations allowed):

buffer-writes buffered writes enabled

async-writes asynchronous writes enabled

read-ahead read-ahead for fixed block size

debug debugging (if compiled into driver)

two-fms write two filemarks when file closed

fast-eod space directly to eod (and lose file number)

no-wait don't wait until rewind, etc. complete

auto-lock automatically lock/unlock drive door

def-writes the block size and density are for writes

can-bsr drive can space backwards as well

no-blklimits drive doesn't support read block limits

can-partitions drive can handle partitioned tapes

scsi2logical seek and tell use SCSI-2 logical block addresses instead of device dependent
addresses

sili Set the SILI bit is when reading in variable block mode. This may speed up reading
blocks shorter than the read byte count. Set this option only if you know that the
drive supports SILI and the HBA reliably returns transfer residual byte counts.
Requires kernel version >= 2.6.26.

sysv enable the System V semantics

stsetoptions
(SCSI tapes) Set selected driver options bits. The methods to specify the bits to set are given
above in the description of stoptions. Allowed only for the superuser.

stclearoptions
(SCSI tapes) Clear selected driver option bits. The methods to specify the bits to clear are
given above in description of stoptions. Allowed only for the superuser.

stshowoptions
(SCSI tapes) Print the currently enabled options for the device. Requires kernel version >= 2.6.26
and sysfs must be mounted at /sys.

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. Allowed only for the superuser.

defblksize
(SCSI tapes) Set the default block size of the device to count bytes. The value -1 disables the
default block size. The block size set by setblk overrides the default until a new tape is
inserted. Allowed only for the superuser.

defdensity
(SCSI tapes) Set the default density code. The value -1 disables the default density. The density
set by setdensity overrides the default until a new tape is inserted. Allowed only for the
superuser.

defdrvbuffer
(SCSI tapes) Set the default drive buffer code. The value -1 disables the default drive buffer
code. The drive buffer code set by drvbuffer overrides the default until a new tape is inserted.
Allowed only for the superuser.

defcompression
(SCSI tapes) Set the default compression state. The value -1 disables the default compression. The
compression state set by compression overrides the default until a new tape is inserted. Allowed
only for the superuser.

sttimeout
sets the normal timeout for the device. The value is given in seconds. Allowed only for the
superuser.

stlongtimeout
sets the long timeout for the device. The value is given in seconds. Allowed only for the
superuser.

stsetcln
set the cleaning request interpretation parameters.

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

       -h, --help
              Print a usage message on standard output and exit successfully.

       -v, --version
              Print version of mt.

       -f, -t The path of the tape device on  which to operate.  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 (note that the actual path to mtio.h  can  vary  per  architecture
              and/or distribution).

NOTES

       The  argument  of  mkpartition specifies the size of the partition in megabytes. If you add a postfix, it
       applies to this definition. For example, argument 1G means 1 giga megabytes, which probably is  not  what
       the user is anticipating.

AUTHOR

       The  program is written by Kai Makisara <Kai.Makisara@kolumbus.fi>, and is currently maintained by Iustin
       Pop <iustin@k1024.org>.

COPYRIGHT

       The program and the manual page are copyrighted by Kai Makisara,  1998-2008.   They  can  be  distributed
       according to the GNU Copyleft.

BUGS

       Please report bugs to <https://github.com/iustin/mt-st>.