[root@lh-1 ~]# docker images Cannot connect to the Docker daemon. Is the docker daemon running on this host? [root@lh-1 ~]# systemctl start docker.service Job for docker.service failed because a timeout was exceeded. See "systemctl status docker.service" and "journalctl -xe" for details. [root@lh-1 ~]# systemctl status docker.service ● docker.service - Docker Application Container Engine Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled) Active: deactivating (final-sigkill) (Result: timeout) since Thu 2016-09-01 01:42:00 UTC; 6 days ago Docs: http://docs.docker.com Process: 18334 ExecStart=/usr/bin/docker-current daemon --exec-opt native.cgroupdriver=systemd $OPTIONS $DOCKER_STORAGE_OPTIONS $DOCKER_NETWORK_OPTIONS $ADD_REGISTRY $BLOCK_REGISTRY $INSECURE_REGISTRY (code=exited, status=1/FAILURE) Main PID: 18334 (code=exited, status=1/FAILURE) CGroup: /system.slice/docker.service Sep 07 15:57:57 lh-1 systemd[1]: Starting Docker Application Container Engine... Sep 07 15:57:57 lh-1 docker-current[18334]: time="2016-09-07T15:57:57.761131231Z" level=error msg="[graphdriver] prior storage driver "devicemapper" failed: ...directory" Sep 07 15:57:57 lh-1 docker-current[18334]: time="2016-09-07T15:57:57.761257149Z" level=fatal msg="Error starting daemon: error initializing graphdriver: open ...directory" Sep 07 15:57:57 lh-1 systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE Sep 07 15:59:27 lh-1 systemd[1]: docker.service stop-sigterm timed out. Killing. Sep 07 16:00:58 lh-1 systemd[1]: docker.service still around after SIGKILL. Ignoring. Sep 07 16:02:28 lh-1 systemd[1]: docker.service stop-final-sigterm timed out. Killing. Hint: Some lines were ellipsized, use -l to show in full.
解决方法：试了一些网上的方法，没有解决，最后reboot了云主机，没启动起来，又到openstack后台启动，问题解决了。