The `aufs` storage driver is deprecated in favor of `overlay2`, and will
be removed in a future release. Users of the `aufs` storage driver are
recommended to migrate to a different storage driver, such as `overlay2`, which
is now the default storage driver.
The `aufs` storage driver facilitates running Docker on distros that have no
support for OverlayFS, such as Ubuntu 14.04 LTS, which originally shipped with
a 3.14 kernel.
Now that Ubuntu 14.04 is no longer a supported distro for Docker, and `overlay2`
is available to all supported distros (as they are either on kernel 4.x, or have
support for multiple lowerdirs backported), there is no reason to continue
maintenance of the `aufs` storage driver.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>