默认docker的空间为10GB，需要在创建的时候，添加参数：
docker run -it -d --name fileserver --storage-opt size=30G docker.io/centos:latest /bin/bash
docker cp /home/www fileserver:/home/
docker commit fileserver www_file:v1，报错：Error response from daemon: ApplyLayer exit status 1 stdout: stderr: write /home/www/school/2008teacher/images/TT_230.JPG: no space left on device
2. 修改配置文件：
/etc/sysconfig/docker-storage