100 lines
3.2 KiB
Groff
100 lines
3.2 KiB
Groff
.\" $NetBSD: vnd.4,v 1.17 2009/12/18 23:37:38 dyoung Exp $
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.\"
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.\" Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
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.\" All rights reserved.
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.\"
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.\" This code is derived from software contributed to The NetBSD Foundation
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.\" by Jason R. Thorpe.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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.\" POSSIBILITY OF SUCH DAMAGE.
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.\"
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.Dd December 18, 2009
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.Dt VND 4
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.Os
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.Sh NAME
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.Nm vnd
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.Nd vnode disk driver
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.Sh SYNOPSIS
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.Cd "pseudo-device vnd"
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.Cd "options VND_COMPRESSION"
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.Sh DESCRIPTION
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The
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.Nm
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driver provides a disk-like interface to a file.
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This is useful for a variety of applications, including swap files
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and building miniroot or floppy disk images.
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.Pp
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This document assumes that you're familiar with how to generate kernels,
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how to properly configure disks and pseudo-devices in a kernel
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configuration file.
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.Pp
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In order to compile in support for the vnd, you must add a line similar
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to the following to your kernel configuration file:
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.Bd -unfilled -offset indent
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pseudo-device vnd # vnode disk driver
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.Ed
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.Pp
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To also compile in support for reading compressed disk images,
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add the following option to your kernel config file:
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.Bd -unfilled -offset indent
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options VND_COMPRESSION # compressed vnd(4)
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.Ed
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.Pp
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Compressed disk images are expected in the cloop2 format,
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they can be created from "normal" disk images by the
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.Xr vndcompress 1
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program.
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.Pp
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There is a run-time utility that is used for configuring
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both compressed and uncompressed
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.Nm vnd Ns s .
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See
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.Xr vnconfig 8
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for more information.
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.Sh FILES
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.Bl -tag -width /dev/XXrXvndX -compact
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.It Pa /dev/{,r}vnd*
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vnd device special files.
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.El
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.Sh SEE ALSO
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.Xr config 1 ,
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.Xr vndcompress 1 ,
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.Xr MAKEDEV 8 ,
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.Xr fsck 8 ,
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.Xr mount 8 ,
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.Xr newfs 8 ,
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.Xr vnconfig 8
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.Sh HISTORY
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The vnode disk driver was originally written at the University of
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Utah.
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The compression handling is based on code by
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.An Cliff Wright
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.Aq cliff@snipe444.org .
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.Sh BUGS
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The
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.Nm
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driver does not work if the file does not reside in a local filesystem.
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.Pp
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The
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.Nm
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driver does not work if the file is sparse.
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