cgroup がマウント出来なかったみたいなエラーが出た際の対処
エラーログは以下
$ sudo docker daemon
INFO[0000] Listening for HTTP on unix (/var/run/docker.sock)
INFO[0000] Option DefaultDriver: bridge
INFO[0000] Option DefaultNetwork: bridge
INFO[0000] Firewalld running: false
WARN[0000] Your kernel does not support cgroup memory limit: mountpoint for memory not found
WARN[0000] mountpoint for cpu not found
FATA[0000] Error starting daemon: Devices cgroup isn't mounted
参考になったStackOverflow
http://stackoverflow.com/questions/32002882/error-starting-docker-daemon-on-ubuntu-14-04-devices-cgroup-isnt-mounted
/etc/default/grub の以下を編集する
GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"