Content-type: text/html
Manpage of UNIONFS
UNIONFS
Section: Maintenance Commands (8)
Updated: January 2006
Index
Return to Main Contents
NAME
Unionfs - a unification file system for Linux
SYNOPSIS
unionctl
UNION
ACTION [
OPTIONS
]
unionctl
UNION
--add
[
--before
BRANCH
|
--after
BRANCH
] [
--mode
(rw|ro|nfsro) ]
DIRECTORY
unionctl
UNION
--remove
BRANCH
unionctl
UNION
--mode
BRANCH
(rw|ro|nfsro)
unionctl
UNION
--list
DESCRIPTION
unionctl
is used to control a unionfs file system. The first argument is a union, which
is the mount point of unionfs, or any file within unionfs. The second argument
is an action. Currently
unionctl
supports file actions: --add, --remove, --mode, --list and --query. Further
arguments are action dependent.
When a branch is required as an argument, it can be specified in two ways. The
easiest way is to specify the path to the branch. If the path is used multiple
times in the union, the highest priority branch will be used. A branch can
also be specified as an index starting from zero.
ACTIONS
- --add
-
add a branch into a union. By default a read-write branch will be added as the
first component of the union.
The order of branches can be modified with --before and --after. Each of these
takes a single branch as an argument. If --before is specified the new branch
will be added before the specified branch; and if --after is specified the new
branch will be added after the specified branch.
Finally, --mode will set the permissions on the new branch. --mode requires
one argument, which is "rw" for a read-write branch, "ro" for a
read-only branch and "nfsro" for read-only access on NFS shares (see
unionfs(4) for further information).
Note: The directory to add must be the last argument.
- --remove
-
removes a branch from a union. Branches with open files can not be removed.
--query
option.
To remove a branch,
unionctl
performs an ioctl that operates on a file descriptor. If the root directory
is opened, then the branch will necessarily be busy.
- --mode
-
sets the permissions of a branch. --mode requires two arguments, the first is
the branch to operate on; and the second is what mode to set. The allowed
modes are "rw" for read-write access, "ro" for read-only access and "nfsro" for
read-only access on NFS shares (see unionfs(4) for further information).
- --list
-
list branches within the union (and also their permissions).
- --query
-
lists the branches where a given file exists. --query requires one argument :
the name of the file to be examined. The output is a list of branches where
the file exists and the permissions of the branches.
AUTHORS
Charles Wright <cwright@cs.sunysb.edu>,
Mohammad Zubair <mzubair@ic.sunysb.edu>,
Erez Zadok <ezk@cs.sunysb.edu>
SEE ALSO
unionfs(4),
uniondbg(8),
http://unionfs.filesystems.org/
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- ACTIONS
-
- AUTHORS
-
- SEE ALSO
-
This document was created by
man2html,
using the manual pages.
Time: 13:01:55 GMT, October 20, 2006