aufs (also known as unionfs) is the oldest but probably the most mature and stable layered filesystem available for Docker. This storage driver is generally fast to start and efficient in terms of storage and memory overhead. If your kernel has been built with support for this driver, Docker will default to it, but generally, outside of Ubuntu and only with the linux-image-extra-$(uname -r) package installed, most distributions do not add that driver to their kernels, nor do they have it available, so most likely your machine will not be able to run it. You could download the kernel source and recompile it with aufs support, but generally, this is such a nightmare of a maintenance that you might as well choose a different storage driver if it is not readily available. You can use grep aufs /proc/filesystems to check whether your machine has the aufs kernel module enabled and available.

Note that the aufs driver can only be used on ext4 and xfs filesystems.