docker安装后启动失败，解决方案

docker安装后启动失败

yum安装docker之后，执行启动命令 systemctl start docker 报错

报错信息：

Jul 15 03:12:29 localhost.localdomain systemd[1]: docker-storage-setup.service: main process exited, code=exited, status=1/FAILURE
Jul 15 03:12:29 localhost.localdomain systemd[1]: Failed to start Docker Storage Setup.
-- Subject: Unit docker-storage-setup.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker-storage-setup.service has failed.
-- 
-- The result is failed.
Jul 15 03:12:29 localhost.localdomain systemd[1]: Unit docker-storage-setup.service entered failed state.
Jul 15 03:12:29 localhost.localdomain systemd[1]: docker-storage-setup.service failed.
Jul 15 03:12:29 localhost.localdomain 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.
Jul 15 03:12:29 localhost.localdomain dockerd-current[3233]: time="2020-07-15T03:12:29.890730928+08:00" level=warning msg="could not change group
Jul 15 03:12:29 localhost.localdomain dockerd-current[3233]: time="2020-07-15T03:12:29.904337819+08:00" level=info msg="libcontainerd: new contai
Jul 15 03:12:30 localhost.localdomain dockerd-current[3233]: time="2020-07-15T03:12:30.918024841+08:00" level=warning msg="overlay2: the backing 
Jul 15 03:12:31 localhost.localdomain dockerd-current[3233]: Error starting daemon: SELinux is not supported with the overlay2 graph driver on th
Jul 15 03:12:31 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
Jul 15 03:12:31 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.
Jul 15 03:12:31 localhost.localdomain systemd[1]: Unit docker.service entered failed state.
Jul 15 03:12:31 localhost.localdomain systemd[1]: docker.service failed.
Jul 15 03:12:31 localhost.localdomain polkitd[957]: Unregistered Authentication Agent for unix-process:3182:801311 (system bus name :1.25, object

解决方案：

vi /etc/sysconfig/docker 

DNS='--selinux-enabled --log-driver=journald --signature-verification=false