NAME
vnd —
vnode disk driver
SYNOPSIS
pseudo-device vnd
options VND_COMPRESSION
DESCRIPTION
Thevnd driver provides a disk-like interface to a file.
This is useful for a variety of applications, including swap files and
building miniroot or floppy disk images.
This document assumes that you're familiar with how to generate kernels and how to properly configure disks and pseudo-devices in a kernel configuration file.
In order to compile in support for the
vnd, you must add a line similar to the following to
your kernel configuration file:
pseudo-device vnd # vnode disk driver
To also compile in support for reading compressed disk images, add the following option to your kernel config file:
options VND_COMPRESSION # compressed vnd(4)
Compressed disk images are expected in the cloop2 format. They can be created from “normal” disk images by the vndcompress(1) program.
There is a run-time utility that is used for configuring both
compressed and uncompressed vnds; see
vnconfig(8) for more information.
FILES
- /dev/{,r}vnd*
- vnd device special files.
SEE ALSO
config(1), vndcompress(1), fsck(8), MAKEDEV(8), mount(8), newfs(8), vnconfig(8)
HISTORY
The vnode disk driver was originally written at the University of Utah. The compression handling is based on code by Cliff Wright ⟨cliff@snipe444.org⟩.
BUGS
The vnd driver does not work if the file
does not reside in a local filesystem.