创建docker镜像时，执行删除命令报错：
rm: can't remove '/usr/local/tomcat/webapps/ROOT': Directory not empty执行 docker info看下如果有这个警告：
WARNING: overlay: the backing xfs filesystem is formatted without d_type support, which leads to incorrect behavior.
Reformat the filesystem with ftype=1 to enable d_type support.
Running without d_type support will not be supported in future releases.
WARNING: bridge-nf-call-ip6tables is disabled
磁盘的驱动问题，需要配置下：
vi /etc/systemd/system/multi-user.target.wants/docker.service
修改ExecStart的值为：
ExecStart=/usr/bin/dockerd --storage-driver=devicemapper
#执行
systemctl daemon-reload
systemctl restart docker这个问题应该是在centos7.2的版本上会有，所以我们建议用CentOS7.4