how to mount aufs filesystem?

I've been learning docker and decided to try out the unionfs aufs. But I couldn't find a way to do it. I tried mount -t aufs but it complained that aufs was unknown. $ sudo mount -t aufs -o dirs=./container-layer:./image-layer4:./image-layer3:./image-layer2:./image-layer1 none ./mnt mount: unknown filesystem type 'aufs' I've searched the Internet but still can't figure out a way to mount aufs filesystem. I'd appriciate it if someone can tell how to mount aufs filesystem or just redirect me to some links. **OS**: Ubuntu16.04 **uname -a**: Linux myzone 4.14.13-041413-generic #201801101001 SMP Wed Jan 10 10:02:53 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux By the way, no **aufs** in /proc/filesystem and aufs-tools was installed.