1.\" $NetBSD: mt.1,v 1.27 2001/12/20 19:31:51 wiz Exp $ 2.\" 3.\" Copyright (c) 1981, 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)mt.1 8.1 (Berkeley) 6/6/93 35.\" 36.Dd June 6, 1993 37.Dt MT 1 38.Os 39.Sh NAME 40.Nm mt 41.Nd magnetic tape manipulation 42.Sh SYNOPSIS 43.Nm 44.Op Fl f Ar tapename 45.Ar command 46.Op Ar count 47.Sh DESCRIPTION 48The 49.Nm 50program is used to give commands to a magnetic tape drive. 51By default 52.Nm 53performs the requested operation once. 54Operations may be performed multiple times by specifying 55.Ar count . 56.Pp 57Note 58that 59.Ar tapename 60must reference a raw (not block) tape device. 61If 62.Ar tapename 63is of the form 64.Qq host:tapename , 65or 66.Qq user@host:tapename , 67.Nm 68writes to the named tape device on the remote host using 69.Xr rmt 8 . 70.Pp 71The 72.Xr rmt 8 73process on the remote host is typically initiated via 74.Xr rsh 1 , 75although an alternate method such as 76.Xr ssh 1 77can be specified via the 78.Ev RCMD_CMD 79environment variable. 80.Pp 81The available commands are listed below. 82Only as many characters as are required to uniquely identify a command 83need be specified. 84.Bl -tag -width "eof, weof" 85.It Cm asf 86Move forward 87.Ar count 88files from the beginning of the tape. This is accomplished by a rewind 89followed by fsf 90.Ar count . 91.It Cm eof , weof 92Write 93.Ar count 94end-of-file marks at the current position on the tape. 95.It Cm fsf 96Forward space 97.Ar count 98files. 99.It Cm fsr 100Forward space 101.Ar count 102records. 103.It Cm bsf 104Back space 105.Ar count 106files. 107.It Cm bsr 108Back space 109.Ar count 110records. 111.It Cm rewind 112Rewind the tape 113(Count is ignored). 114.It Cm offline , rewoffl 115Rewind the tape and place the tape unit off-line 116(Count is ignored). 117.It Cm status 118Print status information about the tape unit 119(Count is ignored). 120.It Cm retension 121Retensions the tape (if this operation is supported by the tape unit, 122count is ignored). 123.It Cm erase 124Erases the tape (if this operation is supported by the tape unit, 125count is ignored). 126.It Cm eew 127Enable or disabled early warning EOM behaviour. 128.Ar Count 129is set to nonzero to enable, zero to disable. 130.It Cm eom 131Forward space to the end of recorded media 132(Count is ignored). 133.It Cm blocksize , setblk 134Set the tape blocksize to 135.Ar count 136bytes. 137A 138.Ar count 139of zero sets variable blocksize. 140.It Cm density , setdensity 141Set the tape density code to 142.Ar count 143as specified in the 144.Tn SCSI-3 145specification. See the 146.Sx DENSITY CODES 147section for a list of codes for commonly used media types. 148.It Cm rdspos 149Read the logical block position of the tape (not all tape 150drives support this feature, count is ignored). 151.It Cm rdhpos 152Read the hardware block position of the tape (not all tape 153drives support this feature, count is ignored). 154.It Cm setspos 155Set the logical block position of the tape to 156.Ar count 157(not all tape drives support this feature). 158.It Cm sethpos 159Set the hardware block position of the tape to 160.Ar count 161(not all tape drives support this feature). 162.It Cm compress 163If 164.Ar count 165is zero, disable compression. 166Otherwise enable compression (not all tape drives support this feature). 167.El 168.Pp 169If a tape name is not specified, and the environment variable 170.Ev TAPE 171is not set, then 172.Nm 173uses the device 174.Pa /dev/nrst0 . 175.Sh EXIT STATUS 176.Nm 177returns a 0 exit status when the operation(s) were successful, 1781 if the command was unrecognized, and 2 if an operation failed. 179.Sh DENSITY CODES 180The SCSI-3 specification defines a number of density codes for 181various tape media, some of which are listed here. Note that 182many tape drive vendors also define model-specific codes. 183.Pp 184.Bl -column "Code" "Format" -compact 185.It Em "Code Format" 186.It Li 0 Ta Device default 187.It Li 1 Ta 1/2" 800 bpi 188.It Li 2 Ta 1/2" 1600 bpi 189.It Li 3 Ta 1/2" 6250 bpi 190.It Li 4 Ta QIC-11 191.It Li 5 Ta QIC-24 192.It Li 15 Ta QIC-120 193.It Li 16 Ta QIC-150 194.It Li 17 Ta QIC-320/525 195.It Li 18 Ta QIC-1320/1350 196.It Li 19 Ta DDS 197.It Li 28 Ta QIC-385M 198.It Li 29 Ta QIC-410M 199.It Li 30 Ta QIC-1000C 200.It Li 31 Ta QIC-2100C 201.It Li 32 Ta QIC-6GB 202.It Li 33 Ta QIC-20GB 203.It Li 34 Ta QIC-2GB 204.It Li 35 Ta QIC-875M 205.It Li 36 Ta DDS-2 206.It Li 37 Ta DDS-3 207.It Li 38 Ta DDS-4 208.El 209.Sh ENVIRONMENT 210If the following environment variables exist, they are utilized by 211.Nm "" . 212.Bl -tag -width Fl 213.It Ev TAPE 214.Nm 215uses device filename given in the 216.Ev TAPE 217environment variable if the 218.Ar tapename 219argument is not given. 220.It Ev RCMD_CMD 221.Nm 222will use 223.Ev RCMD_CMD 224rather than 225.Pa /usr/bin/rsh 226to invoke 227.Xr rmt 8 228on a remote machine. 229The full path name must be specified. 230.El 231.Sh FILES 232.Bl -tag -width /dev/rst* -compact 233.It Pa /dev/rst* 234Raw 235.Tn SCSI 236tape device 237.It Pa /dev/rmt* 238Raw magnetic tape device 239.El 240.Sh SEE ALSO 241.Xr dd 1 , 242.Xr ioctl 2 , 243.Xr mtio 4 , 244.Xr st 4 , 245.Xr environ 7 246.Sh HISTORY 247The 248.Nm 249utility appeared in 250.Bx 4.3 . 251