mt(1) User Commands mt(1)NAMEmt - magnetic tape control
SYNOPSISmt [-f tapename] command... [count]
DESCRIPTION
The mt utility sends commands to a magnetic tape drive. If -f tapename
is not specified, the environment variable TAPE is used. If TAPE does
not exist, mt uses the device /dev/rmt/0n.
OPTIONS
The following options are supported:
-f tapename Specifies the raw tape device.
OPERANDS
The following operands are supported:
count 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.
command The following available commands that can be sent to a mag‐
netic tape drive are supported. Only as many characters as
are required to uniquely identify a command need be speci‐
fied.
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 sequen‐
tial 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 exam‐
ple, bssf 4 searches backwards to the first place
where there are 4 sequential file marks and posi‐
tions to the BOP side of the 4th file mark.
This command is not supported by all drives.
eof Writes count EOF marks at the current position on
weof 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 exam‐
ple, fssf 4 searches forwards to the first place
where there are 4 sequential file marks and posi‐
tions 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 ollowed 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 for‐
mat. See st(7D) 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 com‐
pletes, 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 Rewinds the tape and, if appropriate, takes
rewoffl 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.
EXIT STATUS
0 All operations were successful.
1 Command was unrecognized or mt was unable to open the specified
tape drive.
2 An operation failed.
FILES
/dev/rmt/* magnetic tape interface
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWcsu │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOtar(1), tcopy(1), ar.h(3HEAD), attributes(5), mtio(7I), st(7D)BUGS
Not all devices support all options. Some options are hardware-depen‐
dent. Refer to the corresponding device manual page.
mt is architecture sensitive. Heterogeneous operation (that is, SPARC
to x86 or the reverse) is not supported.
SunOS 5.11 21 Jun 2007 mt(1)
