NAME

       aumvdown - moves-down a file between aufs branches

SYNOPSIS

       aumvdown [options] file_in_aufs ...

DESCRIPTION

       "aumvdown"  command  finds  the first branch where the given file exists, copies it to the
       next lower writable branch, and then removes the file on the first branch.

       There are several conditions to achieve the operation.

              ·   It is obvious that when the file exists between the first and  the  next  lower
                  writable  branches,  or hidden by the whiteout or directory's opaque-ness, then
                  the operation will fail. Because it breaks the consistency in aufs world.

              ·   If a "opaque"-ed directory exists in the ancestors of the  file  and  it  would
                  hide the moved-down file, then the operation will fail.

                  Similary  if  a  whiteout  (in  effect)  exists on any branch betwee source and
                  destination branch and it would hide  the moved-down file, then  the  operation
                  will  fail  too.   Note that the whiteout on "=ro" branch is not in effect, but
                  "=ro+wh" branch.

              ·   Files in use (both in aufs world and in branch filesystem) are not be handled.

              ·   Hard-linked files are not be handled.  For  such  file,  remount  aufs  or  use
                  auplink(8) or aubrsync(8).

              ·   Removed files are not be handled since it has no name.

              ·   Directories  are not be handled since the action doesn't behave recursively and
                  the moving-down an empty dir has less meaning.

OPTIONS

       -b | --lower-branch-id
              -B | --upper-branch-id Specify the source/target branch by its id.  You can  obtain
              the branch id via sysfs.

       -i | --interactive
              Prompt to the user for every given file.

       -k | --keep-upper
              Don't unlink the upper source file after copying-down.

       -o | --overwrite-lower
              Overwrite the lower target file if it exists.

       -r | --allow-ro-lower
              Do  the  operation  even  if  the  lower branch is marked as readonly in aufs world
              ("=ro"). Note that the natively readonly filesystems (mounted with "-o ro") are not
              operatable still even if you specify this option.

       -R | --allow-ro-upper
              Do  the  operation  even  if  the  upper branch is marked as readonly in aufs world
              ("=ro"). Note that the natively readonly filesystems (mounted with "-o ro") are not
              operatable still even if you specify this option.

       -v | --verbose
              Make it verbose particularly for the error cases.

       -h | --help
              Shows the command syntax.

SEE ALSO

       aufs(5)

COPYRIGHT

       Copyright © 2011-2019 Junjiro R. Okajima

AUTHOR

       Junjiro R. Okajima