1.\" $NetBSD: vnd.4,v 1.1 1995/12/30 18:10:48 thorpej Exp $ 2.\" 3.\" Copyright (c) 1995 Jason R. Thorpe. 4.\" 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 for the NetBSD Project 17.\" by Jason R. Thorpe. 18.\" 4. Neither the name of the author 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR 23.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30.\" 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.\" $FreeBSD: src/share/man/man4/vn.4,v 1.6.2.4 2002/04/15 05:48:55 asmodai Exp $ 35.\" 36.Dd December 30, 1995 37.Dt VN 4 38.Os 39.Sh NAME 40.Nm vn 41.Nd vnode disk driver 42.Sh SYNOPSIS 43.Cd "pseudo-device vn" 44.Sh DESCRIPTION 45The 46.Nm 47driver uses swap or a file as backing store to abstract-out a character and 48block device which may then be used like a disk. The 49.Nm 50driver supports both labeled and unlabeled pseudo-disks and is useful for 51a variety of applications, including swap files and building mini-root, 52floppy, or CDRom disk images. 53.Nm 54may also be used to create temporary swap-backed filesystems, such as /tmp, 55in a somewhat less memory-hungry manner than MFS. 56.Pp 57This document assumes that you're familiar with how to generate kernels, 58how to properly configure disks and pseudo-devices in a kernel 59configuration file. 60.Pp 61In order to compile in support for the 62.Nm , 63you must add a line similar 64to the following to your kernel configuration file: 65.Bd -unfilled -offset indent 66pseudo-device vn #Vnode driver 67.Ed 68.Pp 69.Nm 70may also exist as a kernel module to be automatically loaded into the 71system when you run the vnconfig command for the first time. 72.Pp 73There is a run-time utility that is used for configuring 74.Nm Ns 's . 75See 76.Xr vnconfig 8 77for more information. 78.Sh BUGS 79The 80.Nm 81driver does not work if the file does not reside in a local filesystem. 82.Sh FILES 83/dev/{,r}vn* - vn device special files. 84.Pp 85.Sh HISTORY 86The vnode disk driver was originally written at the University of 87Utah and was substantially modified by 88.Fx 89developers to add 90swap-backed support. 91.Sh SEE ALSO 92.Xr config 8 , 93.Xr fsck 8 , 94.Xr MAKEDEV 8 , 95.Xr mount 8 , 96.Xr newfs 8 , 97.Xr vnconfig 8 98