FreeBSD manual
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UNIONFS(5) FreeBSD File Formats Manual UNIONFS(5)
NAME
unionfs - UNION FS
SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
option UNIONFS
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
unionfs_load="YES"
DESCRIPTION
The UNIONFS driver is an implementation of a stackable unification
filesystem.
SEE ALSO
mount_unionfs(8)
STANDARDS
J. S. Pendry and M. K. McKusick, Union mounts in 4.4BSD-Lite, Proceedings
of the USENIX Technical Conference on UNIX and Advanced Computing
Systems, December 1995.
P. H. Kamp and R. N. M. Watson, Jails: Confining the omnipotent root,
Proceedings of the Second International System Administration and
Networking Conference (SANE2000), May 2000.
HISTORY
The unionfs device driver first appeared in FreeBSD 5.0.
AUTHORS
The unionfs device driver was written by Jan-Simon Pendry for 4.4BSD and
Masanori OZAWA <ozawa@ongs.co.jp> reimplemented the handling of the
locking for FreeBSD 7.0. The manual page was written by Gordon Bergling
<gbe@FreeBSD.org>.
BUGS
Please see the mount_unionfs(8) manual page for a list of bugs regarding
the unionfs filesystem.
FreeBSD 14.0-RELEASE-p6 April 27, 2020 FreeBSD 14.0-RELEASE-p6