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. The version of mt is printed with the -v or
16 --version option. The path of the tape device on which to operate can
17 be given with the -f or -t option. If neither of those options is
18 given, and the environment variable TAPE is set, it is used. Other‐
19 wise, a default device defined in the file /usr/include/sys/mtio.h is
20 used.
21 Some operations optionally take an argument or repeat count, which can
23 be given after the operation name and defaults to 1. The postfix k , M
24 , or G can be used to give counts in units of 1024, 1024 * 1024, or
25 1024 * 1024 * 1024, respectively.
26 The available operations are listed below. Unique abbreviations are
28 accepted. Not all operations are available on all systems, or work on
29 all types of tape drives.
30 fsf Forward space count files. The tape is positioned on the first
32 block of the next file.
33 fsfm Forward space past count file marks, then backward space one
35 file record. This leaves the tape positioned on the last block
36 of the file that is count-1 files past the current file.
37 bsf Backward space count files. The tape is positioned on the last
39 block of the previous file.
40 bsfm Backward space past count file marks, then forward space one
42 file record. This leaves the tape positioned on the first block
43 of the file that is count-1 files before the current file.
44 asf The tape is positioned at the beginning of the count file. Posi‐
46 tioning is done by first rewinding the tape and then spacing
47 forward over count filemarks.
48 fsr Forward space count records.
50 bsr Backward space count records.
52 fss (SCSI tapes) Forward space count setmarks.
54 bss (SCSI tapes) Backward space count setmarks.
56 eod, seod
58 Space to end of valid data. Used on streamer tape drives to
59 append data to the logical end of tape.
60 rewind Rewind the tape.
62 offline, rewoffl, eject
64 Rewind the tape and, if applicable, unload the tape.
65 retension
67 Rewind the tape, then wind it to the end of the reel, then
68 rewind it again.
69 weof, eof
71 Write count EOF marks at current position.
72 wset (SCSI tapes) Write count setmarks at current position (only SCSI
74 tape).
75 erase Erase the tape.
77 status Print status information about the tape unit. (If the density
79 code is "no translation" in the status output, this does not
80 affect working of the tape drive.)
81 seek (SCSI tapes) Seek to the count block on the tape. This opera‐
83 tion is available on some Tandberg and Wangtek streamers and
84 some SCSI-2 tape drives. The block address should be obtained
85 from a tell call earlier.
86 tell (SCSI tapes) Tell the current block on tape. This operation is
88 available on some Tandberg and Wangtek streamers and some SCSI-2
89 tape drives.
90 setpartition
92 (SCSI tapes) Switch to the partition determined by count. The
93 default data partition of the tape is numbered zero. Switching
94 partition is available only if enabled for the device, the
95 device supports multiple partitions, and the tape is formatted
96 with multiple partitions.
97 partseek
99 (SCSI tapes) The tape position is set to block count in the par‐
100 tition given by the argument after count. The default partition
101 is zero.
102 mkpartition
104 (SCSI tapes) Format the tape with one (count is zero) or two
105 partitions (count gives the size of the second partition in
106 megabytes). The tape drive must be able to format partitioned
107 tapes with initiator-specified partition size and partition sup‐
108 port must be enabled for the drive.
109 load (SCSI tapes) Send the load command to the tape drive. The drives
111 usually load the tape when a new cartridge is inserted. The
112 argument count can usually be omitted. Some HP changers load
113 tape n if the count 10000 + n is given (a special funtion in the
114 Linux st driver).
115 lock (SCSI tapes) Lock the tape drive door.
117 unlock (SCSI tapes) Unlock the tape drive door.
119 setblk (SCSI tapes) Set the block size of the drive to count bytes per
121 record.
122 setdensity
124 (SCSI tapes) Set the tape density code to count. The proper
125 codes to use with each drive should be looked up from the drive
126 documentation.
127 densities
129 (SCSI tapes) Write explanation of some common density codes to
130 standard output.
131 drvbuffer
133 (SCSI tapes) Set the tape drive buffer code to number. The
134 proper value for unbuffered operation is zero and "normal"
135 buffered operation one. The meanings of other values can be
136 found in the drive documentation or, in the case of a SCSI-2
137 drive, from the SCSI-2 standard.
138 compression
140 (SCSI tapes) The compression within the drive can be switched on
141 or off using the MTCOMPRESSION ioctl. Note that this method is
142 not supported by all drives implementing compression. For
143 instance, the Exabyte 8 mm drives use density codes to select
144 compression.
145 stoptions
147 (SCSI tapes) Set the driver options bits for the device to the
148 defined values. Allowed only for the superuser. The bits can be
149 set either by ORing the option bits from the file
150 /usr/include/linux/mtio.h to count, or by using the following
151 keywords (as many keywords can be used on the same line as nec‐
152 essary, unambiguous abbreviations allowed):
153 buffer-writes buffered writes enabled
155 async-writes asynchronous writes enabled
157 read-ahead read-ahead for fixed block size
159 debug debugging (if compiled into driver)
161 two-fms write two filemarks when file closed
163 fast-eod space directly to eod (and lose file number)
165 no-wait don't wait until rewind, etc. complete
167 auto-lock automatically lock/unlock drive door
169 def-writes the block size and density are for writes
171 can-bsr drive can space backwards as well
173 no-blklimits drive doesn't support read block limits
175 can-partitions drive can handle partitioned tapes
177 scsi2logical seek and tell use SCSI-2 logical block addresses
179 instead of device dependent addresses
180 sili Set the SILI bit is when reading in variable
182 block mode. This may speed up reading blocks
183 shorter than the read byte count. Set this option
184 only if you know that the drive supports SILI and
185 the HBA reliably returns transfer residual byte
186 counts. Requires kernel version >= 2.6.26.
187 sysv enable the System V semantics
189 stsetoptions
191 (SCSI tapes) Set selected driver options bits. The methods to
192 specify the bits to set are given above in the description of
193 stoptions. Allowed only for the superuser.
194 stclearoptions
196 (SCSI tapes) Clear selected driver option bits. The methods to
197 specify the bits to clear are given above in description of
198 stoptions. Allowed only for the superuser.
199 stshowoptions
201 (SCSI tapes) Print the currently enabled options for the device.
202 Requires kernel version >= 2.6.26 and sysfs must be mounted at
203 /sys.
204 stwrthreshold
206 (SCSI tapes) The write threshold for the tape device is set to
207 count kilobytes. The value must be smaller than or equal to the
208 driver buffer size. Allowed only for the superuser.
209 defblksize
211 (SCSI tapes) Set the default block size of the device to count
212 bytes. The value -1 disables the default block size. The block
213 size set by setblk overrides the default until a new tape is
214 inserted. Allowed only for the superuser.
215 defdensity
217 (SCSI tapes) Set the default density code. The value -1 disables
218 the default density. The density set by setdensity overrides the
219 default until a new tape is inserted. Allowed only for the supe‐
220 ruser.
221 defdrvbuffer
223 (SCSI tapes) Set the default drive buffer code. The value -1
224 disables the default drive buffer code. The drive buffer code
225 set by drvbuffer overrides the default until a new tape is
226 inserted. Allowed only for the superuser.
227 defcompression
229 (SCSI tapes) Set the default compression state. The value -1
230 disables the default compression. The compression state set by
231 compression overrides the default until a new tape is inserted.
232 Allowed only for the superuser.
233 sttimeout
235 sets the normal timeout for the device. The value is given in
236 seconds. Allowed only for the superuser.
237 stlongtimeout
239 sets the long timeout for the device. The value is given in sec‐
240 onds. Allowed only for the superuser.
241 stsetcln
243 set the cleaning request interpretation parameters.
244 mt exits with a status of 0 if the operation succeeded, 1 if the opera‐
246 tion or device name given was invalid, or 2 if the operation failed.
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249 The program is written by Kai Makisara <Kai.Makisara@kolumbus.fi>.
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252 The program and the manual page are copyrighted by Kai Makisara,
253 1998-2008. They can be distributed according to the GNU Copyleft.
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256 st(4)
257 April 2008 MT(1)