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: src/usr.bin/mt/mt.1,v 1.19.2.8 2002/11/08 11:35:57 joerg Exp $ 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 48The 49.Nm 50utility is used to give commands to a magnetic tape drive. 51By default 52.Nm 53performs the requested operation once. Operations 54may be performed multiple times by specifying 55.Ar count . 56Note 57that 58.Ar tapename 59must reference a raw (not block) tape device. 60.Pp 61The available commands are listed below. Only as many 62characters as are required to uniquely identify a command 63need be specified. 64.Bl -tag -width "eof, weof" 65.It Cm weof 66Write 67.Ar count 68end-of-file marks at the current position on the tape. 69.It Cm smk 70Write 71.Ar count 72setmarks at the current position on the tape. 73.It Cm fsf 74Forward space 75.Ar count 76files. 77.It Cm fsr 78Forward space 79.Ar count 80records. 81.It Cm fss 82Forward space 83.Ar count 84setmarks. 85.It Cm bsf 86Backward space 87.Ar count 88files. 89.It Cm bsr 90Backward space 91.Ar count 92records. 93.It Cm bss 94Backward space 95.Ar count 96setmarks. 97.It Cm rdhpos 98Read Hardware block position. 99Some drives do not support this. 100The block 101number reported is specific for that hardware only. 102The count argument is 103ignored. 104.It Cm rdspos 105Read SCSI logical block position. 106Some drives do not support this. 107The 108count argument is ignored. 109.It Cm sethpos 110Set Hardware block position. 111Some drives do not support this. 112The count 113argument is interpreted as a hardware block to which to position the tape. 114.It Cm setspos 115Set SCSI logical block position. 116Some drives do not support this. 117The count 118argument is interpreted as a SCSI logical block to which to position the tape. 119.It Cm rewind 120Rewind the tape 121(Count is ignored). 122.It Cm offline , rewoffl 123Rewind the tape and place the tape unit off-line 124(Count is ignored). 125.It Cm erase 126Erase the tape. 127A count of 0 disables long erase, which is on by default. 128.It Cm retension 129Re-tension the tape 130(one full wind forth and back, Count is ignored). 131.It Cm status 132Print status information about the tape unit. 133For SCSI magnetic tape devices, 134the current operating modes of density, blocksize, and whether compression 135is enabled is reported. 136The current state of the driver (what it thinks that 137it is doing with the device) is reported. 138If the driver knows the relative 139position from BOT (in terms of filemarks and records), it prints that. 140Note 141that this information is not definitive (only BOT, End of Recorded Media, and 142hardware or SCSI logical block position (if the drive supports such) are 143considered definitive tape positions). 144.It Cm errstat 145Print (and clear) error status information about this device. 146For every normal 147operation (e.g., a read or a write) and every control operation (e.g,, a 148rewind), the driver stores up the last command executed and it's associated 149status and any residual counts (if any). This command retrieves and prints this 150information. 151If possible, this also clears any latched error information. 152.It Cm blocksize 153Set the block size for the tape unit. Zero means variable-length 154blocks. 155.It Cm density 156Set the density for the tape unit. For the density codes, see below. 157The density value could be given either numerically, or as a string, 158corresponding to the 159.Dq Reference 160field. If the string is abbreviated, it will be resolved in the order 161shown in the table, and the first matching entry will be used. If the 162given string and the resulting canonical density name do not match 163exactly, an informational message is printed about what the given 164string has been taken for. 165.It Cm geteotmodel 166Fetch and print out the current EOT filemark model. 167The model states how 168many filemarks will be written at close if a tape was being written. 169.It Cm seteotmodel 170Set (from the 171.Ar count 172argument) 173and print out the current and EOT filemark model. 174Typically this will be 175.Ar 2 176filemarks, but some devices (typically QIC cartridge drives) can 177only write 178.Ar 1 179filemark. 180Currently you can only choose a value of 181.Ar 1 182or 183.Ar 2 . 184.It Cm eom 185Forward space to end of recorded medium 186(Count is ignored). 187.It Cm eod 188Forward space to end of data, identical to 189.Cm eom . 190.It Cm comp 191Set compression mode. 192There are currently several possible values for the compression mode: 193.Pp 194.Bl -tag -width 9n -compact 195.It off 196Turn compression off. 197.It on 198Turn compression on. 199.It none 200Same as 201.Ar off . 202.It enable 203Same as 204.Ar on . 205.It IDRC 206IBM Improved Data Recording Capability compression (0x10). 207.It DCLZ 208DCLZ compression algorithm (0x20). 209.El 210.Pp 211In addition to the above recognized compression keywords, the user can 212supply a numeric compression algorithm for the tape drive to use. In most 213cases, simply turning the compression 214.Sq on 215will have the desired effect of enabling the default compression algorithm 216supported by the drive. If this is not the case (see the 217.Cm status 218display to see which compression algorithm is currently in use), the user 219can manually specify one of the supported compression keywords (above), or 220supply a numeric compression value. 221.El 222.Pp 223If a tape name is not specified, and the environment variable 224.Ev TAPE 225does not exist; 226.Nm 227uses the device 228.Pa /dev/nsa0 . 229.Pp 230The 231.Nm 232utility returns a 0 exit status when the operation(s) were successful, 2331 if the command was unrecognized, and 2 if an operation failed. 234.Pp 235The following density table was taken from the 236.Sq Historical sequential access density codes 237table (A-1) in Revision 11 of the SCSI-3 Stream Device Commands (SSC) 238working draft, dated November 11, 1997. 239.Pp 240The different density codes are as follows: 241.Pp 242.Dl "0x0 default for device" 243.Dl "0xE reserved for ECMA" 244.Bd -literal -offset 3n 245Value Width Tracks Density Code Type Reference Note 246 mm in bpmm bpi 2470x01 12.7 (0.5) 9 32 (800) NRZI R X3.22-1983 2 2480x02 12.7 (0.5) 9 63 (1,600) PE R X3.39-1986 2 2490x03 12.7 (0.5) 9 246 (6,250) GCR R X3.54-1986 2 2500x05 6.3 (0.25) 4/9 315 (8,000) GCR C X3.136-1986 1 2510x06 12.7 (0.5) 9 126 (3,200) PE R X3.157-1987 2 2520x07 6.3 (0.25) 4 252 (6,400) IMFM C X3.116-1986 1 2530x08 3.81 (0.15) 4 315 (8,000) GCR CS X3.158-1987 1 2540x09 12.7 (0.5) 18 1,491 (37,871) GCR C X3.180 2 2550x0A 12.7 (0.5) 22 262 (6,667) MFM C X3B5/86-199 1 2560x0B 6.3 (0.25) 4 63 (1,600) PE C X3.56-1986 1 2570x0C 12.7 (0.5) 24 500 (12,690) GCR C HI-TC1 1,6 2580x0D 12.7 (0.5) 24 999 (25,380) GCR C HI-TC2 1,6 2590x0F 6.3 (0.25) 15 394 (10,000) GCR C QIC-120 1,6 2600x10 6.3 (0.25) 18 394 (10,000) GCR C QIC-150 1,6 2610x11 6.3 (0.25) 26 630 (16,000) GCR C QIC-320 1,6 2620x12 6.3 (0.25) 30 2,034 (51,667) RLL C QIC-1350 1,6 2630x13 3.81 (0.15) 1 2,400 (61,000) DDS CS X3B5/88-185A 5 2640x14 8.0 (0.315) 1 1,703 (43,245) RLL CS X3.202-1991 5 2650x15 8.0 (0.315) 1 1,789 (45,434) RLL CS ECMA TC17 5 2660x16 12.7 (0.5) 48 394 (10,000) MFM C X3.193-1990 1 2670x17 12.7 (0.5) 48 1,673 (42,500) MFM C X3B5/91-174 1 2680x18 12.7 (0.5) 112 1,673 (42,500) MFM C X3B5/92-50 1 2690x19 12.7 (0.5) 128 2,460 (62,500) RLL C DLTapeIII 6,7 2700x1A 12.7 (0.5) 128 3,214 (81,633) RLL C DLTapeIV(20) 6,7 2710x1B 12.7 (0.5) 208 3,383 (85,937) RLL C DLTapeIV(35) 6,7 2720x1C 6.3 (0.25) 34 1,654 (42,000) MFM C QIC-385M 1,6 2730x1D 6.3 (0.25) 32 1,512 (38,400) GCR C QIC-410M 1,6 2740x1E 6.3 (0.25) 30 1,385 (36,000) GCR C QIC-1000C 1,6 2750x1F 6.3 (0.25) 30 2,666 (67,733) RLL C QIC-2100C 1,6 2760x20 6.3 (0.25) 144 2,666 (67,733) RLL C QIC-6GB(M) 1,6 2770x21 6.3 (0.25) 144 2,666 (67,733) RLL C QIC-20GB(C) 1,6 2780x22 6.3 (0.25) 42 1,600 (40,640) GCR C QIC-2GB(C) ? 2790x23 6.3 (0.25) 38 2,666 (67,733) RLL C QIC-875M ? 2800x24 3.81 (0.15) 1 2,400 (61,000) CS DDS-2 5 2810x25 3.81 (0.15) 1 3,816 (97,000) CS DDS-3 5 2820x26 3.81 (0.15) 1 3,816 (97,000) CS DDS-4 5 2830x27 8.0 (0.315) 1 3,056 (77,611) RLL CS Mammoth 5 2840x28 12.7 (0.5) 36 1,491 (37,871) GCR C X3.224 1 2850x29 12.7 (0.5) 2860x2A 2870x2B 12.7 (0.5) 3 ? ? ? C X3.267 5 2880x41 12.7 (0.5) 208 3,868 (98,250) RLL C DLTapeIV(40) 6,7 2890x48 12.7 (0.5) 448 5,236 (133,000) PRML C SDLTapeI(110) 6,8 2900x49 12.7 (0.5) 448 7,598 (193,000) PRML C SDLTapeI(160) 6,8 291.Ed 292.Bd -literal -offset 3n 293Code Description Type Description 294---------------- ---------------- 295NRZI Non return to zero, change on ones R Reel-to-reel 296GCR Group code recording C Cartridge 297PE Phase encoded CS Cassette 298IMFM Inverted modified frequency modulation 299MFM Modified frequency modulation 300DDS DAT data storage 301RLL Run length limited 302PRML Partial Response Maximum Likelihood 303.Ed 304.Bd -literal -offset 3n 305NOTES 3061. Serial recorded. 3072. Parallel recorded. 3083. Old format known as QIC-11. 3095. Helical scan. 3106. This is not an American National Standard. The reference is based on 311 an industry standard definition of the media format. 3127. DLT recording: serially recorded track pairs (DLTapeIII and 313 DLTapeIV(20)), or track quads (DLTapeIV(35) and DLTapeIV(40)). 3148. Super DLT (SDLT) recording: 56 serially recorded logical tracks with 315 8 physical tracks each. 316.Ed 317.Sh ENVIRONMENT 318If the following environment variable exists, it is utilized by 319.Nm . 320.Bl -tag -width Fl 321.It Ev TAPE 322The 323.Nm 324utility checks the 325.Ev TAPE 326environment variable if the 327argument 328.Ar tapename 329is not given. 330.El 331.Sh FILES 332.Bl -tag -width /dev/*rst[0-9]*xx -compact 333.It Pa /dev/*rsa[0-9]* 334SCSI magnetic tape interface 335.El 336.Sh SEE ALSO 337.Xr dd 1 , 338.Xr ioctl 2 , 339.Xr mtio 4 , 340.Xr sa 4 , 341.Xr environ 7 342.Sh HISTORY 343The 344.Nm 345command appeared in 346.Bx 4.3 . 347.Pp 348Extensions regarding the 349.Xr st 4 350driver appeared in 351.Bx 386 0.1 352as a separate 353.Xr st 1 354command, and have been merged into the 355.Nm 356command in 357.Fx 2.1 . 358.Pp 359The former 360.Cm eof 361command that used to be a synonym for 362.Cm weof 363has been abandoned in 364.Fx 2.1 365since it was often confused with 366.Cm eom , 367which is fairly dangerous. 368