修改images目录

找了好久，在stackoverflow上找到一个修改办法

这个是跑在CENTOS和RHEL7上才能用到以下办法 

This solution works on Red Hat 7.2 & Docker 1.12.0

Edit the file /lib/systemd/system/docker.service in your text editor.

add -g /path/to/docker/ at the end of ExecStart directive. The complete line should look like this.

ExecStart=/usr/bin/dockerd -g /path/to/docker/

Execute the below command

systemctl daemon-reload

systemctl restart docker

Execute the command to check docker directory

docker info | grep "loop file\|Dir"

If you have /etc/sysconfig/docker file in Red Hat or docker 1.7.1 check this answer.