TRANSLUCENCY(8)

NAME
translucency - overlays two file-systems

SYNOPSIS
insmod translucency.o
    echo "/given/dir -> /other/dir" > /proc/sys/translucency/0
        echo 65534 > /proc/sys/translucency/uid
            echo 4 > /proc/sys/translucency/flags

DESCRIPTION
translucency will install modified syscall handlers that redirect file operations in such a way as to logically merge two directories (presumably on different file-systems, on different media) into one directory.

OPTIONS
Options can no longer be given at module loading time. Instead they have to be written into the appropriate /proc/sys/translucency/<option> file.

from=/given/dir
    lower layer - write access is redirected away

to=/other/dir
    upper layer - written files go here

uid=<int>
    limits overlaying to user with ID <int>

gid=<int>
    limits overlaying to group with ID <int>

flags=<int>
    change the module's operation with a bitwise combination of the following:
    1 no_translucency: turns module off
        2 no_copyonwrite: kernel does not try to copy files if needed (i.e. for appending)
            4 no_getdents: only entries in lower layer are shown in directory listings
                8 do_downcase: downcase all filenames to avoid inconsistencies on case-insensitive filesystems

AUTHOR
Bernhard M. Wiedemann <b.m.w@gmx.net>
    David Bird <dbird@bpnetworks.com>

KNOWN BUGS
    Double entries for overlaid files are shown
        Bad symlink handling
            Functionality has to be extended...
                There are probably serious buffer overflow conditions left in this module. Suggestions for improving the security of this module are welcome!

BUGS
Report bugs through the bug-tracking system at http://translucency.sourceforge.net

SEE ALSO
The effect is somewhat similar to: inheriting (ifs), stacking (fist), translucent (tfs), loopback (lofs), overlaying (ovlfs), and BSDs union file system