I ran into this error while preparing docker-in-docker.
WARN Couldn't run auplink before unmount /var/lib/docker/aufs/mnt/*: exit status 22
ERRO Handler for POST /v1.30/containers/create returned error: error creating aufs mount to /var/lib/docker/aufs/mnt/*: invalid argument
In my case, I just needed to add VOLUME /var/lib/docker
to the Dockerfile for outer docker image. In this way we can set Backing Filesystem: extfs
(in docker info
).