现象：Centos7.3通过yum安装完docker后，启动docker失败
机器的系统版本：CentOS Linux release 7.3.1611 (Core)
centos7,执行完安装命令： yum -y install docker
执行启动命令： systemctl start docker ,报如下错误：
[root@localhost lib]# systemctl start 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 lib]# systemctl status docker
● docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since 六 2018-11-17 01:10:23 CST; 1min 20s ago
Docs: http://docs.docker.com
Process: 11743 ExecStart=/usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker-runc --exec-opt native.cgroupdriver=systemd --userland-proxy-path=/usr/libexec/docker/docker-proxy-current --init-path=/usr/libexec/docker/docker-init-current --seccomp-profile=/etc/docker/seccomp.json $OPTIONS $DOCKER_STORAGE_OPTIONS $DOCKER_NETWORK_OPTIONS $ADD_REGISTRY $BLOCK_REGISTRY $INSECURE_REGISTRY $REGISTRIES (code=exited, status=1/FAILURE)
Main PID: 11743 (code=exited, status=1/FAILURE)
11月 17 01:10:21 localhost.localdomain systemd[1]: Starting Docker Application Container Engine...
11月 17 01:10:21 localhost.localdomain dockerd-current[11743]: time="2018-11-17T01:10:21.635497926+08:00" level=warning msg=...und"
11月 17 01:10:21 localhost.localdomain dockerd-current[11743]: time="2018-11-17T01:10:21.637443612+08:00" level=info msg="li...750"
11月 17 01:10:23 localhost.localdomain dockerd-current[11743]: Error starting daemon: SELinux is not supported with the over...lse)
11月 17 01:10:23 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
11月 17 01:10:23 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine.
11月 17 01:10:23 localhost.localdomain systemd[1]: Unit docker.service entered failed state.
11月 17 01:10:23 localhost.localdomain systemd[1]: docker.service failed.
Hint: Some lines were ellipsized, use -l to show in full.
报错信息：Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. Either boot into a newer kernel or disable selinux in docker (--selinux-enabled=false)
原因分析： 此linux的内核中的SELinux不支持 overlay2 graph driver ，解决方法有两个，要么启动一个新内核，要么就在docker里禁用selinux，--selinux-enabled=false
重新编辑docker配置文件：
[root@localhost lib]# vi /etc/sysconfig/docker
# /etc/sysconfig/docker
# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--selinux-enabled=false --log-driver=journald --signature-verification=false'
if [ -z "${DOCKER_CERT_PATH}" ]; then
DOCKER_CERT_PATH=/etc/docker
"/etc/sysconfig/docker" 26L, 1100C written
[root@localhost lib]# systemctl start docker
[root@localhost lib]#
重新启动docker服务：systemctl start docker