freebsd-nq/share/man/man4/vn.4

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.\" $NetBSD: vnd.4,v 1.1 1995/12/30 18:10:48 thorpej Exp $
.\"
.\" Copyright (c) 1995 Jason R. Thorpe.
.\" All rights reserved.
.\"
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.\" by Jason R. Thorpe.
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.Dd December 30, 1995
.Dt VN 4
.Os
.Sh NAME
.Nm vn
.Nd vnode disk driver
.Sh SYNOPSIS
.Cd "pseudo-device vn" Op Ar count
.Sh DESCRIPTION
The
.Nm
driver provides a disk-like interface to a file. This is useful for
a variety of applications, including swap files and building mini-root
or floppy disk images.
.Pp
This document assumes that you're familiar with how to generate kernels,
how to properly configure disks and pseudo-devices in a kernel
configuration file.
.Pp
In order to compile in support for the
.Nm vn ,
you must add a line similar
to the following to your kernel configuration file:
.Bd -unfilled -offset indent
pseudo-device vn 4 #Vnode driver
.Ed
.Pp
The
.Ar count
argument is how many
.Nm vn Ns 's
memory is allocated for a boot time. In this example, no more than 4
.Nm vn Ns 's
may be configured.
.Pp
There is a run-time utility that is used for configuring
.Nm vn Ns 's .
See
.Xr vnconfig 8
for more information.
.Sh BUGS
The
.Nm
driver does not work if the file does not reside in a local filesystem.
.Sh FILES
/dev/{,r}vn* - vn device special files.
.Pp
.Sh HISTORY
The vnode disk driver was originally written at the University of
Utah.
.Sh SEE ALSO
.Xr MAKEDEV 8 ,
.Xr config 8 ,
.Xr fsck 8 ,
.Xr mount 8 ,
.Xr newfs 8 ,
.Xr vnconfig 8 .