1. 停止docker服务

   [ ]# systemctl stop docker

2. 创建devicemapper目录

   [ ]# mkdir -p /docker/devicemapper/devicemapper

3. 进入刚创建的devicemapper目录

   [ ~]# cd /docker/devicemapper/devicemapper/

4. 使用dd创建data文件，这里创建500G

   [ devicemapper]# dd if=/dev/zero of=data bs=1G count=0 seek=500

5. 启动docker服务

   [ ~]# systemctl start docker