aufs

aufs (AnotherUnionFS in version 1, but advanced multi layered unification filesystem since version 2) implements a union mount for Linux file systems.

Developed by Junjiro Okajima in 2006, aufs is a complete rewriting of the earlier UnionFS. It aimed to improve reliability and performance, but also introduced some new concepts, like writable branch balancing, and other improvements - some of which are now implemented in the UnionFS 2.x branch.

Use

Several Linux distributions have chosen aufs as a replacement for UnionFS, including:

• Knoppix live CD Linux distribution - since the end of 2006, "for better stability & performance"
• NimbleX since version 2008. Switched simultaneously with Linux-Live
• Slax (and Linux-Live scripts in general) since version 6
• Xandros Linux distribution, available in the ASUS Eee PC model 901.
• Arch Linux 2009.08-2011.7
• Ubuntu 10.04 LTS Live CD
• Debian 6.0 Live media
• Gentoo Linux LiveDVD 11.0
• Gentoo Linux LiveDVD 11.2
• Gentoo Linux LiveDVD 12.0
• Salix Live via Linux-Live scripts until version 13.1.1 and via SaLT from version 13.37.
• Puppy Linux LiveCD 5.3.3. All versions run fully in RAM with changes saved to disk on shutdown.

See also

• File system
• Union mount, describing the concept of merging file system branches
• UnionFS, an older union mount project, developed by Professor Erez Zadok and his team at Stony Brook University.

External links

• AuFS project homepage
• a simple example