1MT(1) General Commands Manual MT(1)
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6 mt - control magnetic tape drive operation
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9 mt [-h] [-f device] operation [count] [arguments...]
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12 This manual page documents the tape control program mt. mt performs
13 the given operation, which must be one of the tape operations listed
14 below, on a tape drive. The commands can also be listed by running the
15 program with the -h option.
16 Some operations optionally take an argument or repeat count, which can
18 be given after the operation name and defaults to 1. The postfix k , M
19 , or G can be used to give counts in units of 1024, 1024 * 1024, or
20 1024 * 1024 * 1024, respectively.
21 The available operations are listed below. Unique abbreviations are
23 accepted. Not all operations are available on all systems, or work on
24 all types of tape drives.
25 fsf Forward space count files. The tape is positioned on the first
27 block of the next file.
28 fsfm Forward space count files, then backward space one record. This
30 leaves the tape positioned at the last block of the file that is
31 count - 1 files past the current file.
32 bsf Backward space count files. The tape is positioned on the last
34 block of the previous file.
35 bsfm Backward space count files, then forward space one record. This
37 leaves the tape positioned at the first block of the file that
38 is count - 1 files before the current file.
39 asf The tape is positioned at the beginning of the count file. Posi‐
41 tioning is done by first rewinding the tape and then spacing
42 forward over count filemarks.
43 fsr Forward space count records.
45 bsr Backward space count records.
47 fss (SCSI tapes) Forward space count setmarks.
49 bss (SCSI tapes) Backward space count setmarks.
51 eod, seod
53 Space to end of valid data. Used on streamer tape drives to ap‐
54 pend data to the logical end of tape.
55 rewind Rewind the tape.
57 offline, rewoffl, eject
59 Rewind the tape and, if applicable, unload the tape.
60 retension
62 Rewind the tape, then wind it to the end of the reel, then
63 rewind it again.
64 weof, eof
66 Write count EOF marks at current position.
67 wset (SCSI tapes) Write count setmarks at current position (only SCSI
69 tape).
70 erase Erase the tape. Note that this is a long erase, which on modern
72 (high-capacity) tapes can take many hours, and which usually
73 can't be aborted.
74 status Print status information about the tape unit. (If the density
76 code is "no translation" in the status output, this does not af‐
77 fect working of the tape drive.)
78 seek (SCSI tapes) Seek to the count block on the tape. This opera‐
80 tion is available on some Tandberg and Wangtek streamers and
81 some SCSI-2 tape drives. The block address should be obtained
82 from a tell call earlier.
83 tell (SCSI tapes) Tell the current block on tape. This operation is
85 available on some Tandberg and Wangtek streamers and some SCSI-2
86 tape drives.
87 setpartition
89 (SCSI tapes) Switch to the partition determined by count. The
90 default data partition of the tape is numbered zero. Switching
91 partition is available only if enabled for the device, the de‐
92 vice supports multiple partitions, and the tape is formatted
93 with multiple partitions.
94 partseek
96 (SCSI tapes) The tape position is set to block count in the par‐
97 tition given by the argument after count. The default partition
98 is zero.
99 mkpartition
101 (SCSI tapes) Format the tape with one (count is zero) or two
102 partitions (count gives the size of the second partition in
103 megabytes). If the count is positive, it specifies the size of
104 partition 1. From kernel version 4.6, if the count is negative,
105 it specifies the size of partition 0. With older kernels, a neg‐
106 ative argument formats the tape with one partition. The tape
107 drive must be able to format partitioned tapes with initiator-
108 specified partition size and partition support must be enabled
109 for the drive.
110 load (SCSI tapes) Send the load command to the tape drive. The drives
112 usually load the tape when a new cartridge is inserted. The ar‐
113 gument count can usually be omitted. Some HP changers load tape
114 n if the count 10000 + n is given (a special function in the
115 Linux st driver).
116 lock (SCSI tapes) Lock the tape drive door.
118 unlock (SCSI tapes) Unlock the tape drive door.
120 setblk (SCSI tapes) Set the block size of the drive to count bytes per
122 record.
123 setdensity
125 (SCSI tapes) Set the tape density code to count. The proper
126 codes to use with each drive should be looked up from the drive
127 documentation.
128 densities
130 (SCSI tapes) Write explanation of some common density codes to
131 standard output.
132 drvbuffer
134 (SCSI tapes) Set the tape drive buffer code to number. The
135 proper value for unbuffered operation is zero and "normal"
136 buffered operation one. The meanings of other values can be
137 found in the drive documentation or, in the case of a SCSI-2
138 drive, from the SCSI-2 standard.
139 compression
141 (SCSI tapes) The compression within the drive can be switched on
142 or off using the MTCOMPRESSION ioctl. Note that this method is
143 not supported by all drives implementing compression. For in‐
144 stance, the Exabyte 8 mm drives use density codes to select com‐
145 pression.
146 stoptions
148 (SCSI tapes) Set the driver options bits for the device to the
149 defined values. Allowed only for the superuser. The bits can be
150 set either by ORing the option bits from the file /usr/in‐
151 clude/linux/mtio.h to count, or by using the following keywords
152 (as many keywords can be used on the same line as necessary, un‐
153 ambiguous abbreviations allowed):
154 buffer-writes buffered writes enabled
156 async-writes asynchronous writes enabled
158 read-ahead read-ahead for fixed block size
160 debug debugging (if compiled into driver)
162 two-fms write two filemarks when file closed
164 fast-eod space directly to eod (and lose file number)
166 no-wait don't wait until rewind, etc. complete
168 auto-lock automatically lock/unlock drive door
170 def-writes the block size and density are for writes
172 can-bsr drive can space backwards as well
174 no-blklimits drive doesn't support read block limits
176 can-partitions drive can handle partitioned tapes
178 scsi2logical seek and tell use SCSI-2 logical block addresses
180 instead of device dependent addresses
181 sili Set the SILI bit is when reading in variable
183 block mode. This may speed up reading blocks
184 shorter than the read byte count. Set this option
185 only if you know that the drive supports SILI and
186 the HBA reliably returns transfer residual byte
187 counts. Requires kernel version >= 2.6.26.
188 sysv enable the System V semantics
190 stsetoptions
192 (SCSI tapes) Set selected driver options bits. The methods to
193 specify the bits to set are given above in the description of
194 stoptions. Allowed only for the superuser.
195 stclearoptions
197 (SCSI tapes) Clear selected driver option bits. The methods to
198 specify the bits to clear are given above in description of
199 stoptions. Allowed only for the superuser.
200 stshowoptions
202 (SCSI tapes) Print the currently enabled options for the device.
203 Requires kernel version >= 2.6.26 and sysfs must be mounted at
204 /sys.
205 stwrthreshold
207 (SCSI tapes) The write threshold for the tape device is set to
208 count kilobytes. The value must be smaller than or equal to the
209 driver buffer size. Allowed only for the superuser.
210 defblksize
212 (SCSI tapes) Set the default block size of the device to count
213 bytes. The value -1 disables the default block size. The block
214 size set by setblk overrides the default until a new tape is in‐
215 serted. Allowed only for the superuser.
216 defdensity
218 (SCSI tapes) Set the default density code. The value -1 disables
219 the default density. The density set by setdensity overrides the
220 default until a new tape is inserted. Allowed only for the supe‐
221 ruser.
222 defdrvbuffer
224 (SCSI tapes) Set the default drive buffer code. The value -1
225 disables the default drive buffer code. The drive buffer code
226 set by drvbuffer overrides the default until a new tape is in‐
227 serted. Allowed only for the superuser.
228 defcompression
230 (SCSI tapes) Set the default compression state. The value -1
231 disables the default compression. The compression state set by
232 compression overrides the default until a new tape is inserted.
233 Allowed only for the superuser.
234 sttimeout
236 sets the normal timeout for the device. The value is given in
237 seconds. Allowed only for the superuser.
238 stlongtimeout
240 sets the long timeout for the device. The value is given in sec‐
241 onds. Allowed only for the superuser.
242 stsetcln
244 set the cleaning request interpretation parameters.
245 mt exits with a status of 0 if the operation succeeded, 1 if the opera‐
247 tion or device name given was invalid, or 2 if the operation failed.
248
250 -h, --help
251 Print a usage message on standard output and exit successfully.
252 -v, --version
254 Print version of mt.
255 -f, -t The path of the tape device on which to operate. If neither of
257 those options is given, and the environment variable TAPE is
258 set, it is used. Otherwise, a default device defined in the
259 file /usr/include/sys/mtio.h is used (note that the actual path
260 to mtio.h can vary per architecture and/or distribution).
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263 The argument of mkpartition specifies the size of the partition in
264 megabytes. If you add a postfix, it applies to this definition. For ex‐
265 ample, argument 1G means 1 giga megabytes, which probably is not what
266 the user is anticipating.
267
269 The program is written by Kai Makisara <Kai.Makisara@kolumbus.fi>, and
270 is currently maintained by Iustin Pop <iustin@k1024.org>.
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273 The program and the manual page are copyrighted by Kai Makisara,
274 1998-2008. They can be distributed according to the GNU Copyleft.
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277 Please report bugs to <https://github.com/iustin/mt-st>.
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280 st(4)
281 April 2008 MT(1)