1.\" Copyright (c) 1981, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. All advertising materials mentioning features or use of this software 14.\" must display the following acknowledgement: 15.\" This product includes software developed by the University of 16.\" California, Berkeley and its contributors. 17.\" 4. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)mt.1 8.1 (Berkeley) 6/6/93 34.\" $FreeBSD$ 35.\" 36.Dd June 6, 1993 37.Dt MT 1 38.Os 39.Sh NAME 40.Nm mt 41.Nd magnetic tape manipulating program 42.Sh SYNOPSIS 43.Nm 44.Op Fl f Ar tapename 45.Ar command 46.Op Ar count 47.Sh DESCRIPTION 48.Nm \&Mt 49is used to give commands to a magnetic tape drive. 50By default 51.Nm 52performs the requested operation once. Operations 53may be performed multiple times by specifying 54.Ar count . 55Note 56that 57.Ar tapename 58must reference a raw (not block) tape device. 59.Pp 60The available commands are listed below. Only as many 61characters as are required to uniquely identify a command 62need be specified. 63.Bl -tag -width "eof, weof" 64.It Cm weof 65Write 66.Ar count 67end-of-file marks at the current position on the tape. 68.It Cm smk 69Write 70.Ar count 71setmarks at the current position on the tape. 72.It Cm fsf 73Forward space 74.Ar count 75files. 76.It Cm fsr 77Forward space 78.Ar count 79records. 80.It Cm fss 81Forward space 82.Ar count 83setmarks. 84.It Cm bsf 85Backward space 86.Ar count 87files. 88.It Cm bsr 89Backward space 90.Ar count 91records. 92.It Cm bss 93Backward space 94.Ar count 95setmarks. 96.It Cm rdhpos 97Read Hardware block position. 98Some drives do not support this. 99The block 100number reported is specific for that hardware only. 101The count argument is 102ignored. 103.It Cm rdspos 104Read SCSI logical block position. 105Some drives do not support this. 106The 107count argument is ignored. 108.It Cm sethpos 109Set Hardware block position. 110Some drives do not support this. 111The count 112argument is interpreted as a hardware block to which to position the tape. 113.It Cm setspos 114Set SCSI logical block position. 115Some drives do not support this. 116The count 117argument is interpreted as a SCSI logical block to which to position the tape. 118.It Cm rewind 119Rewind the tape 120(Count is ignored). 121.It Cm offline , rewoffl 122Rewind the tape and place the tape unit off-line 123(Count is ignored). 124.It Cm erase 125Erase the tape. 126A count of 0 disables long erase, which is on by default. 127.It Cm retension 128Re-tension the tape 129(one full wind forth and back, Count is ignored). 130.It Cm status 131Print status information about the tape unit. 132For SCSI magnetic tape devices, 133the current operating modes of density, blocksize, and whether compression 134is enabled is reported. 135The current state of the driver (what it thinks that 136it is doing with the device) is reported. 137If the driver knows the relative 138position from BOT (in terms of filemarks and records), it prints that. 139Note 140that this information is not definitive (only BOT, End of Recorded Media, and 141hardware or SCSI logical block position (if the drive supports such) are 142considered definitive tape positions). 143.It Cm errstat 144Print (and clear) error status information about this device. 145For every normal 146operation (e.g., a read or a write) and every control operation (e.g,, a 147rewind), the driver stores up the last command executed and it's associated 148status and any residual counts (if any). This command retrieves and prints this 149information. 150If possible, this also clears any latched error information. 151.It Cm blocksize 152Set the block size for the tape unit. Zero means variable-length 153blocks. 154.It Cm density 155Set the density for the tape unit. For the density codes, see below. 156The density value could be given either numerically, or as a string, 157corresponding to the 158.Dq Reference 159field. If the string is abbreviated, it will be resolved in the order 160shown in the table, and the first matching entry will be used. If the 161given string and the resulting canonical density name do not match 162exactly, an informational message is printed about what the given 163string has been taken for. 164.It Cm geteotmodel 165Fetch and print out the current EOT filemark model. 166The model states how 167many filemarks will be written at close if a tape was being written. 168.It Cm seteotmodel 169Set (from the 170.Ar count 171argument) 172and print out the current and EOT filemark model. 173Typically this will be 174.Ar 2 175filemarks, but some devices (typically QIC cartridge drives) can 176only write 177.Ar 1 178filemark. 179Currently you can only choose a value of 180.Ar 1 181or 182.Ar 2 . 183.It Cm eom 184Forward space to end of recorded medium 185(Count is ignored). 186.It Cm eod 187Forward space to end of data, identical to 188.Cm eom . 189.It Cm comp 190Set compression mode. 191There are currently several possible values for the compression mode: 192.Pp 193.Bl -tag -width 9n -compact 194.It off 195Turn compression off. 196.It on 197Turn compression on. 198.It none 199Same as 200.Ar off . 201.It enable 202Same as 203.Ar on . 204.It IDRC 205IBM Improved Data Recording Capability compression (0x10). 206.It DCLZ 207DCLZ compression algorithm (0x20). 208.El 209.Pp 210In addition to the above recognized compression keywords, the user can 211supply a numeric compression algorithm for the tape drive to use. In most 212cases, simply turning the compression 213.Sq on 214will have the desired effect of enabling the default compression algorithm 215supported by the drive. If this is not the case (see the 216.Cm status 217display to see which compression algorithm is currently in use), the user 218can manually specify one of the supported compression keywords (above), or 219supply a numeric compression value. 220.El 221.Pp 222If a tape name is not specified, and the environment variable 223.Ev TAPE 224does not exist; 225.Nm 226uses the device 227.Pa /dev/nsa0 . 228.Pp 229.Nm \&Mt 230returns a 0 exit status when the operation(s) were successful, 2311 if the command was unrecognized, and 2 if an operation failed. 232.Pp 233The following density table was taken from the 234.Sq Historical sequential access density codes 235table (A-1) in Revision 11 of the SCSI-3 Stream Device Commands (SSC) 236working draft, dated November 11, 1997. 237.Pp 238The different density codes are as follows: 239.Pp 240.Dl "0x0 default for device 241.Dl "0xE reserved for ECMA 242.Bd -literal -offset 3n 243Value Width Tracks Density Code Type Reference Note 244 mm in bpmm bpi 2450x01 12.7 (0.5) 9 32 (800) NRZI R X3.22-1983 2 2460x02 12.7 (0.5) 9 63 (1,600) PE R X3.39-1986 2 2470x03 12.7 (0.5) 9 246 (6,250) GCR R X3.54-1986 2 2480x05 6.3 (0.25) 4/9 315 (8,000) GCR C X3.136-1986 1 2490x06 12.7 (0.5) 9 126 (3,200) PE R X3.157-1987 2 2500x07 6.3 (0.25) 4 252 (6,400) IMFM C X3.116-1986 1 2510x08 3.81 (0.15) 4 315 (8,000) GCR CS X3.158-1987 1 2520x09 12.7 (0.5) 18 1,491 (37,871) GCR C X3.180 2 2530x0A 12.7 (0.5) 22 262 (6,667) MFM C X3B5/86-199 1 2540x0B 6.3 (0.25) 4 63 (1,600) PE C X3.56-1986 1 2550x0C 12.7 (0.5) 24 500 (12,690) GCR C HI-TC1 1,6 2560x0D 12.7 (0.5) 24 999 (25,380) GCR C HI-TC2 1,6 2570x0F 6.3 (0.25) 15 394 (10,000) GCR C QIC-120 1,6 2580x10 6.3 (0.25) 18 394 (10,000) GCR C QIC-150 1,6 2590x11 6.3 (0.25) 26 630 (16,000) GCR C QIC-320 1,6 2600x12 6.3 (0.25) 30 2,034 (51,667) RLL C QIC-1350 1,6 2610x13 3.81 (0.15) 1 2,400 (61,000) DDS CS X3B5/88-185A 5 2620x14 8.0 (0.315) 1 1,703 (43,245) RLL CS X3.202-1991 5 2630x15 8.0 (0.315) 1 1,789 (45,434) RLL CS ECMA TC17 5 2640x16 12.7 (0.5) 48 394 (10,000) MFM C X3.193-1990 1 2650x17 12.7 (0.5) 48 1,673 (42,500) MFM C X3B5/91-174 1 2660x18 12.7 (0.5) 112 1,673 (42,500) MFM C X3B5/92-50 1 2670x1C 6.3 (0.25) 34 1,654 (42,000) MFM C QIC-385M 1,6 2680x1D 6.3 (0.25) 32 1,512 (38,400) GCR C QIC-410M 1,6 2690x1E 6.3 (0.25) 30 1,385 (36,000) GCR C QIC-1000C 1,6 2700x1F 6.3 (0.25) 30 2,666 (67,733) RLL C QIC-2100C 1,6 2710x20 6.3 (0.25) 144 2,666 (67,733) RLL C QIC-6GB(M) 1,6 2720x21 6.3 (0.25) 144 2,666 (67,733) RLL C QIC-20GB(C) 1,6 2730x22 6.3 (0.25) 42 1,600 (40,640) GCR C QIC-2GB(C) ? 2740x23 6.3 (0.25) 38 2,666 (67,733) RLL C QIC-875M ? 2750x24 3.81 (0.15) 1 2,400 (61,000) CS DDS-2 5 2760x25 3.81 (0.15) 1 3,816 (97,000) CS DDS-3 5 2770x26 3.81 (0.15) 1 3,816 (97,000) CS DDS-4 5 2780x27 8.0 (0.315) 1 3,056 (77,611) RLL CS Mammoth 5 2790x28 12.7 (0.5) 36 1,491 (37,871) GCR C X3.224 1 2800x29 12.7 (0.5) 2810x2A 2820x2B 12.7 (0.5) 3 ? ? ? C X3.267 5 283.Ed 284.Bd -literal -offset 3n 285Code Description Type Description 286---------------- ---------------- 287NRZI Non return to zero, change on ones R Reel-to-reel 288GCR Group code recording C Cartridge 289PE Phase encoded CS Cassette 290IMFM Inverted modified frequency modulation 291MFM Modified frequency modulation 292DDS DAT data storage 293RLL Run length limited 294.Ed 295.Bd -literal -offset 3n 296NOTES 2971. Serial recorded. 2982. Parallel recorded. 2993. Old format known as QIC-11. 3005. Helical scan. 3016. This is not an American National Standard. The reference is based on 302 an industry standard definition of the media format. 303.Ed 304.Sh ENVIRONMENT 305If the following environment variable exists, it is utilized by 306.Nm . 307.Bl -tag -width Fl 308.It Ev TAPE 309.Nm \&Mt 310checks the 311.Ev TAPE 312environment variable if the 313argument 314.Ar tapename 315is not given. 316.El 317.Sh FILES 318.Bl -tag -width /dev/*rst[0-9]*xx -compact 319.It Pa /dev/*rwt* 320QIC-02/QIC-36 magnetic tape interface 321.It Pa /dev/*rsa[0-9]* 322SCSI magnetic tape interface 323.El 324.Sh SEE ALSO 325.Xr dd 1 , 326.Xr ioctl 2 , 327.Xr ast 4 , 328.Xr mtio 4 , 329.Xr sa 4 , 330.Xr environ 7 331.Sh HISTORY 332The 333.Nm 334command appeared in 335.Bx 4.3 . 336.Pp 337Extensions regarding the 338.Xr st 4 339driver appeared in 340.Bx 386 0.1 341as a separate 342.Xr st 1 343command, and have been merged into the 344.Nm 345command in 346.Fx 2.1 . 347.Pp 348The former 349.Cm eof 350command that used to be a synonym for 351.Cm weof 352has been abandoned in 353.Fx 2.1 354since it was often confused with 355.Cm eom , 356which is fairly dangerous. 357