Aufs

Aufs (Another Union File System) is Article description::an advanced multi-layered unification filesystem. Aufs was originally a re-design and re-implementation of the popular UnionFS, however after adding many new original ideas it became entirely separate from UnionFS. Aufs is considered a UnionFS alternative since it supports many of the same features.

Features

 * The ability to unite several directories into a single virtual filesystem. Calling the member directory as a branch;
 * Specification of the permission flags on each branch (readonly, readwrite, and whiteout-able);
 * Via upper writable branch, internal copyup and whiteout is possible (files and directories on the readonly branch are logically modifiable);
 * Dynamic branch manipulation (add, delete, etc.)

Installation
Emerge the pre-patched package. This will install another set of kernel sources that have had the Aufs4 patches applied. The new sources will show up in using a aufs suffixed name scheme.

If aufs sources are not yet emerged on the system, do so presently:

After the process is finished, list the available sources:

Use to set the symlink to the aufs kernel sources:

Kernel configuration
After the features have been set, build the kernel:

Configuration
In order to work with Aufs, the package is needed; utilities are always necessary for Aufs. This packages should be pulled in when emerging. In the case that it is not, run:

Usage
Check