問題：
[root@localhost ~]# service docker restart
Redirecting to /bin/systemctl restart docker.service
Job for docker.service failed because start of the service was attempted too often. See "systemctl status docker.service" and "journalctl -xe" for details.
然后查看日志內容如下：
-- Unit docker.service has begun starting up. 9月 20 15:23:49 localhost.localdomain dockerd[2591]: unable to configure the Docker daemon with file /etc/docker/daemon.json: unexpected EOF 9月 20 15:23:49 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE 9月 20 15:23:49 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine. -- Subject: Unit docker.service has failed -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit docker.service has failed. -- -- The result is failed. 9月 20 15:23:49 localhost.localdomain systemd[1]: Unit docker.service entered failed state. 9月 20 15:23:49 localhost.localdomain systemd[1]: docker.service failed. 9月 20 15:23:49 localhost.localdomain systemd[1]: docker.service holdoff time over, scheduling restart. 9月 20 15:23:49 localhost.localdomain systemd[1]: start request repeated too quickly for docker.service 9月 20 15:23:49 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine. -- Subject: Unit docker.service has failed -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit docker.service has failed. -- -- The result is failed. 9月 20 15:23:49 localhost.localdomain systemd[1]: Unit docker.service entered failed state. 9月 20 15:23:49 localhost.localdomain systemd[1]: docker.service failed.
解決辦法：
vim /etc/docker/daemon.json
{ "storage-driver": "devicemapper" }
上面內容寫入到這個文件，重啟docker服務器，問題解決！！