问题：

制作镜像的时候报错

devmapper: Thin Pool has 162394 free data blocks which is less than minimum required 163840 free data blocks. Create more free space in thin pool or use dm.min_free_space option to change behavior

解决方案：

运行下面三个命令： 
// 注意，以下三个命令执行时可能出错是正常的。

清理exited进程：

docker rm $(docker ps -q -f status=exited)

清理dangling volumes：

docker volume rm $(docker volume ls -qf dangling=true)

清理dangling image：

docker rmi $(docker images --filter "dangling=true" -q --no-trunc)

devmapper: Thin Pool has 162394 free data blocks which is less than minimum required 163840 free data blocks. Create more free space in thin pool or use dm.min_free_space option to change behavior