Cannot start docker.io with upstart in 16.04

[Marius B. Kotsbak]

The docker daemon is no longer running after upgrading to 16.04 beta:

Cannot connect to the Docker daemon. Is the docker daemon running on this host?

$ /etc/init.d/docker restart
stop: Unknown instance:
start: Rejected send message, 1 matched rules; type="method_call", sender=":1.178" (uid=1001 pid=11507 comm="start docker ") interface="com.ubuntu.Upstart0_6.Job" member="Start" error name="(unset)" requested_reply="0" destination="com.ubuntu.Upstart" (uid=0 pid=1 comm="/sbin/upstart ")

[Marius B. Kotsbak (mariusko)]

I see this that is the likely source of the problem:

$ sudo /usr/bin/docker daemon
FATA[0000] Error starting daemon: error initializing graphdriver: "/var/lib/docker" contains other graphdrivers: devicemapper; Please cleanup or explicitly choose storage driver (-s <DRIVER>)

[Marius B. Kotsbak (mariusko)]

Solved by removing /var/lib/docker/devicemapper

[Michael Hudson-Doyle (mwhudson)]

Which version of docker were you upgrading from/to? I don't have a /var/lib/docker/devicemapper, was that from an older version? (Sorry, I'm not familiar with the history of the docker packaging)

[Marius B. Kotsbak (mariusko)]

I was upgrading from wily version of Docker.io. But I can't find that file/directory in the package. It seems it was created as data files: https://docs.docker.com/engine/userguide/storagedriver/device-mapper-driver/