xref: /netbsd-src/share/man/man4/vnd.4 (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1.\"	$NetBSD: vnd.4,v 1.16 2009/03/26 17:33:41 joerg Exp $
2.\"
3.\" Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
4.\" All rights reserved.
5.\"
6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Jason R. Thorpe.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\"    notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\"    notice, this list of conditions and the following disclaimer in the
16.\"    documentation and/or other materials provided with the distribution.
17.\"
18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28.\" POSSIBILITY OF SUCH DAMAGE.
29.\"
30.Dd February 1, 2006
31.Dt VND 4
32.Os
33.Sh NAME
34.Nm vnd
35.Nd vnode disk driver
36.Sh SYNOPSIS
37.Cd "pseudo-device vnd"
38.Cd "options VND_COMPRESSION"
39.Sh DESCRIPTION
40The
41.Nm
42driver provides a disk-like interface to a file.
43This is useful for a variety of applications, including swap files
44and building miniroot or floppy disk images.
45.Pp
46This document assumes that you're familiar with how to generate kernels,
47how to properly configure disks and pseudo-devices in a kernel
48configuration file.
49.Pp
50In order to compile in support for the vnd, you must add a line similar
51to the following to your kernel configuration file:
52.Bd -unfilled -offset indent
53pseudo-device	vnd		# vnode disk driver
54.Ed
55.Pp
56To also compile in support for reading compressed disk images,
57add the following option to your kernel config file:
58.Bd -unfilled -offset indent
59options        VND_COMPRESSION    # compressed vnd(4)
60.Ed
61.Pp
62Compressed disk images are expected in the cloop2 format,
63they can be created from "normal" disk images by the
64.Xr vndcompress 1
65program.
66.Pp
67There is a run-time utility that is used for configuring
68both compressed and uncompressed
69.Nm vnd Ns s .
70See
71.Xr vnconfig 8
72for more information.
73.Sh FILES
74.Bl -tag -width /dev/XXrXvndX -compact
75.It Pa /dev/{,r}vnd*
76vnd device special files.
77.El
78.Sh SEE ALSO
79.Xr config 1 ,
80.Xr vndcompress 1 ,
81.Xr MAKEDEV 8 ,
82.Xr fsck 8 ,
83.Xr mount 8 ,
84.Xr newfs 8 ,
85.Xr vnconfig 8
86.Sh HISTORY
87The vnode disk driver was originally written at the University of
88Utah.
89The compression handling is based on code by
90.An Cliff Wright
91.Aq cliff@snipe444.org .
92.Sh BUGS
93The
94.Nm
95driver does not work if the file does not reside in a local filesystem.
96