The latest version of rofs-filtered is now at: https://github.com/gburca/rofs-filtered The rest of this document is maintained purely for historical reasons. This FUSE file system allows the user to mount a directory tree as read-only and filter the files shown in the read-only directory tree based on regular expressions found in the rofs-filtered.rc configuration file. See the rofs-filtered.rc file for more details. What's the use of such a file system? Say you have a ton of *.flac music files, along with the transcoded *.mp3 files in the same directory tree structure. Maybe you want to show only one of the formats to music players that can play both flac and mp3 so that the songs don't show up twice. You might also want to show only mp3 files to players that don't understand the flac format. Based on: ROFS - The read-only filesystem for FUSE. Get the latest version from: http://ebixio.com/rofs-filtered/ See the INSTALL file for installation instructions. See below for configuration instructions. On Ubuntu/Debian install: libfuse2, libfuse-dev, fuse-utils Version 2.5 or later of FUSE is required. If needed, it can be obtained from debuntu.org by adding the following line to /etc/apt/sources.list: deb http://repository.debuntu.org/ dapper multiverse See the rofs-filtered.rc file for instructions on how to configure the filtering. This file is installed by default in /usr/local/etc. Mount a directory tree by adding a similar line to /etc/fstab: /full/path/to/rofs-filtered#/the/read/write/device /the/read/only/mount/point fuse defaults,allow_other 0 0 rofs-filtered can also be called directly: rofs-filtered [-c config] [FUSE options] Unmount: fusermount -u /the/read/only/mount/point OR umount /the/read/only/mount/point On some systems, the user will need to be in the "fuse" UNIX group.