VN(4)		       FreeBSD Kernel Interfaces Manual 		 VN(4)

NAME
     vn - vnode disk driver

SYNOPSIS
     pseudo-device vn

DESCRIPTION
     The vn driver uses swap or a file as backing store to abstract-out a
     character and block device which may then be used like a disk.  The vn
     driver supports both labeled and unlabeled pseudo-disks and is useful for
     a variety of applications, including swap files and building mini-root,
     floppy, or CDRom disk images.  vn may also be used to create temporary
     swap-backed filesystems, such as /tmp, in a somewhat less memory-hungry
     manner than MFS.

     This document assumes that you're familiar with how to generate kernels,
     how to properly configure disks and pseudo-devices in a kernel configura-
     tion file.

     In order to compile in support for the vn, you must add a line similar to
     the following to your kernel configuration file:

	   pseudo-device  vn	    #Vnode driver

     vn may also exist as a kernel module to be automatically loaded into the
     system when you run the vnconfig command for the first time.

     There is a run-time utility that is used for configuring vn's.  See
     vnconfig(8) for more information.

BUGS
     The vn driver does not work if the file does not reside in a local
     filesystem.

FILES
     /dev/{,r}vn* - vn device special files.

HISTORY
     The vnode disk driver was originally written at the University of Utah
     and was substantially modified by FreeBSD developers to add swap-backed
     support.

SEE ALSO
     config(8), fsck(8), MAKEDEV(8), mount(8), newfs(8), vnconfig(8)

FreeBSD 4.8		       December 30, 1995		   FreeBSD 4.8