重启报错：
[root@localhost ~]# systemctl restart docker
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
[root@localhost ~]# journalctl -xe
-- The start-up result is done.
12月 19 10:27:58 localhost systemd[1]: Started Docker Storage Setup.
-- Subject: Unit docker-storage-setup.service has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit docker-storage-setup.service has finished starting up.
--
-- The start-up result is done.
12月 19 10:27:58 localhost systemd[1]: Starting Docker Application Container Engine...
-- Subject: Unit docker.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit docker.service has begun starting up.
12月 19 10:27:58 localhost dockerd-current[3480]: time="2018-12-19T10:27:58.101895626+08:00" level=warning
12月 19 10:27:58 localhost dockerd-current[3480]: time="2018-12-19T10:27:58.106879353+08:00" level=info msg
12月 19 10:27:59 localhost dockerd-current[3480]: Error starting daemon: SELinux is not supported with the
12月 19 10:27:59 localhost systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
12月 19 10:27:59 localhost 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.
12月 19 10:27:59 localhost systemd[1]: Unit docker.service entered failed state.
12月 19 10:27:59 localhost systemd[1]: docker.service failed.
12月 19 10:27:59 localhost polkitd[896]: Unregistered Authentication Agent for unix-process:3420:114832 (sy
原因是：
这是由于overlay2不支持造成的，所以我们要关闭它。
解决方法：
vim /etc/sysconfig/docker (修改文件)
DNS='--selinux-enabled --log-driver=journald --signature-verification=false'
if [ -z "${DOCKER_CERT_PATH}" ]; then
DOCKER_CERT_PATH=/etc/docker
fi
重启： systemctl restart docker