diff options
| author | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 15:32:58 -0400 |
|---|---|---|
| committer | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 15:32:58 -0400 |
| commit | 5cb84ec742fd33f78c8022863fadaa8d0d93e176 (patch) | |
| tree | 1a81ca3665e6153923e40db7b0d988f8573ab59c /static/netbsd/man4/mtio.4 | |
| parent | a59214f344567c037d5776879bcfc5fcc1d4d5f6 (diff) | |
feat: Added NetBSD man pages
Diffstat (limited to 'static/netbsd/man4/mtio.4')
| -rw-r--r-- | static/netbsd/man4/mtio.4 | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/static/netbsd/man4/mtio.4 b/static/netbsd/man4/mtio.4 new file mode 100644 index 00000000..65d3ebbe --- /dev/null +++ b/static/netbsd/man4/mtio.4 @@ -0,0 +1,167 @@ +.\" $NetBSD: mtio.4,v 1.17 2010/03/22 18:58:31 joerg Exp $ +.\" +.\" Copyright (c) 1983, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" from: @(#)mtio.4 8.1 (Berkeley) 6/5/93 +.\" +.Dd January 14, 1999 +.Dt MTIO 4 +.Os +.Sh NAME +.Nm mtio +.Nd generic magnetic tape I/O interface +.Sh SYNOPSIS +.In sys/ioctl.h +.In sys/types.h +.In sys/mtio.h +.Sh DESCRIPTION +Magnetic tape has been the computer system backup and data transfer +medium of choice for decades, because it has historically been +cheaper in cost per bit stored, and the formats have been designed +for portability and storage. +However, tape drives have generally been the slowest mass +storage devices attached to any computer system. +.Pp +Magnetic tape comes in a wide variety of formats, from classic 9-track, +through various Quarter Inch Cartridge +.Pq Tn QIC +variants, to more modern systems using 8mm video tape, and +Digital Audio Tape +.Pq Tn DAT . +There have also been a variety of proprietary tape systems, including +.Tn DECtape , +and +.Tn "IBM 3480" . +.Ss UNIX TAPE I/O +Regardless of the specific characteristics of the particular tape +transport mechanism (tape drive), +.Ux +tape I/O has two interfaces: +.Qq block +and +.Qq raw . +I/O through the block interface of a tape device is similar to I/O +through the block special device for a disk driver: the individual +.Xr read 2 +and +.Xr write 2 +calls can be done in any amount of bytes, but all data is buffered +through the system buffer cache, and I/O to the device is done in +1024 byte sized blocks. +This limitation is sufficiently restrictive that the block interface +to tape devices is rarely used. +.Pp +The +.Qq raw +interface differs in that all I/O can be done in arbitrary sized blocks, +within the limitations for the specific device and device driver, +and all I/O is synchronous. +This is the most flexible interface, but since there is very little +that is handled automatically by the kernel, user programs must +implement specific magnetic tape handling routines, which puts the onus +of correctness on the application programmer. +.Ss DEVICE NAME CONVENTIONS +Each magnetic tape subsystem has a couple of special devices +associated with it. +.Pp +The block device is usually named for the driver, e.g. +.Pa /dev/st0 +for unit zero of a +.Xr st 4 +.Tn SCSI +tape drive. +.Pp +The raw device name is the block device name with an +.Qq r +prepended, e.g. +.Pa /dev/rst0 . +.Pp +By default, the tape driver will rewind the tape drive when the +device is closed. +To make it possible for multiple program invocations to +sequentially write multiple files on the same tape, a +.Qq no rewind on close +device is provided, denoted by the letter +.Qq n +prepended to the name of the device, e.g. +.Pa /dev/nst0 , +.Pa /dev/nrst0 . +.Pp +The +.Xr mt 1 +command can be used to explicitly rewind, or otherwise position a +tape at a particular point with the no-rewind device. +.Ss FILE MARK HANDLING +Two end-of-file (EOF) markers mark the end of a tape (EOT), and +one end-of-file marker marks the end of a tape file. +.Pp +By default, the tape driver will write two End Of File (EOF) marks +and rewind the tape when the device is closed after the last write. +.Pp +If the tape is not to be rewound it is positioned with the +head in between the two tape marks, where the next write +will over write the second end-of-file marker. +.Pp +All of the magnetic tape devices may be manipulated with the +.Xr mt 1 +command. +.Pp +A number of +.Xr ioctl 2 +operations are available on raw magnetic tape. +Please see +.In sys/mtio.h +for their definitions. +.\" The following definitions are from +.\" .In sys/mtio.h : +.\" .Bd -literal +.\" there was a copy of sys/mtio.h here. silly. +.\" .Ed +.Pp +The manual pages for specific tape device drivers should list their +particular capabilities and limitations. +.Sh SEE ALSO +.Xr dd 1 , +.Xr mt 1 , +.Xr pax 1 , +.Xr tar 1 , +.Xr st 4 , +.Xr wt 4 +.Sh HISTORY +The +.Nm +manual appeared in +.Bx 4.2 . +.Sh BUGS +The status should be returned in a device independent format. +.Pp +If and when +.Nx +is updated to deal with non-512 byte per sector disk media through the +system buffer cache, perhaps a more sane tape interface can be +implemented. |
