mt(1) User Commands mt(1)
mt - magnetic tape control
mt [-f tapename] command... [count]
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.
The following option is supported:
-f tapename Specifies the raw tape device.
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 may be performed by
command Available commands that can be sent to a magnetic tape
drive. Only as many characters as are required to
uniquely identify a command need be specified.
eof Writes count EOF marks at the current
weof 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.
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.
nbsf Back spaces count files. The tape is
positioned on the first block of the
file. This is equivalent to count+1
bsf's followed by one fsf.
asf Specifies absolute space to count file
number. This is equivalent to a rewind
followed by a fsf count.
If count is specified with any of the following com-
mands, the count is ignored and the command is per-
formed only once.
eom Spaces to the end of recorded media on
the tape. This is useful for appending
files onto previously written tapes.
rewind Rewinds the tape.
offline Rewinds the tape and, if appropriate,
rewoffl takes the drive unit off-line by
unloading the tape.
status Prints status information about the
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.
reserve Allows the tape drive to remain
reserved after closing the device. The
drive must then be explicitly released.
release Re-establishes the default behavior of
releasing at close.
forcereserve Breaks the reservation of the tape
drive held by another host and then
reserves the tape drive. This command
can be executed only with super-user
erase Erases the entire tape. Caution: Some
tape drives have option settings where
only portions of the tape may be
erased. Be sure to select the correct
setting to erase the whole tape. Eras-
ing a tape may take a long time depend-
ing on the device and/or tape. Refer to
the device specific manual for time
config Reads the drives current configuration
from the driver and displays it in
st.conf format. See st(7D) for defini-
tion of fields and there meanings.
0 All operations were successful.
1 Command was unrecognized or mt was unable to open the speci-
fied tape drive.
2 An operation failed.
/dev/rmt/* magnetic tape interface
See attributes(5) for descriptions of the following attributes:
tab() allbox; cw(2.750000i)| cw(2.750000i) lw(2.750000i)|
lw(2.750000i). ATTRIBUTE TYPEATTRIBUTE VALUE AvailabilitySUNWcsu
tar(1), tcopy(1), ar.h(3HEAD), environ(4), attributes(5), mtio( 7I),
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 5.10 1 Sep 2004 mt(1)