docker 常见错误

出现错误:

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
           

sudo systemctl status docker

● docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
   Active: inactive (dead) (Result: exit-code) since 四 2018-09-27 15:47:15 CST; 22min ago
     Docs: https://docs.docker.com
  Process: 25007 ExecStart=/usr/bin/dockerd -H fd:// (code=exited, status=1/FAILURE)
 Main PID: 25007 (code=exited, status=1/FAILURE)

9月 27 15:47:15 xuanwu systemd[1]: Failed to start Docker Application Container Engine.
9月 27 15:47:15 xuanwu systemd[1]: docker.service: Unit entered failed state.
9月 27 15:47:15 xuanwu systemd[1]: docker.service: Failed with result 'exit-code'.
9月 27 15:47:15 xuanwu systemd[1]: docker.service: Service hold-off time over, scheduling restart.
9月 27 15:47:15 xuanwu systemd[1]: Stopped Docker Application Container Engine.
9月 27 15:47:15 xuanwu systemd[1]: docker.service: Start request repeated too quickly.
9月 27 15:47:15 xuanwu systemd[1]: Failed to start Docker Application Container Engine.
           

可能原因:

docker没有启动

sudo service docker start