Provided by: unionfs-utils_1.0.14-1_i386 bug

NAME

       Unionfs - a unification file system for Linux

SYNOPSIS

       unionctl UNION ACTION [ OPTIONS ]

       unionctl  UNION  --add  [  --before  BRANCH | --after BRANCH ] [ --mode
       (rw|ro) ] DIRECTORY

       unionctl UNION --remove BRANCH

       unionctl UNION --mode BRANCH (rw|ro)

       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 either "rw" for  a  read-
              write branch or "ro" for a read-only branch.

              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 "ro"  for  read-only
              access and "rw" for read-write access.

       --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/