AUMVDOWN(8) Linux Aufs User's Manual AUMVDOWN(8)
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.
o 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.
o If a "opaque"-ed directory exists in the ancestors of the
file and it would hide the moved-down file, then the opera-
tion will fail.
Similary if a whiteout (in effect) exists on any branch be-
twee 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.
o Files in use (both in aufs world and in branch filesystem)
are not be handled.
o Hard-linked files are not be handled. For such file, re-
mount aufs or use auplink(8) or aubrsync(8).
o Removed files are not be handled since it has no name.
o Directories are not be handled since the action doesn't be-
have 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 filesys-
tems (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 filesys-
tems (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 (C) 2011-2019 Junjiro R. Okajima
AUTHOR
Junjiro R. Okajima
Linux aufs3.9 and later AUMVDOWN(8)