【docker】 /var/lib/docker/overlay2/ 占用磁盘问题

df -h

查看到下面的路径，占用快满了

而如果把 /var/lib/docker/overlay2/ ，里面的内容删除的话，docker pull要报错 

failed to register layer: symlink ../9f01f71de427212082349a7c0e59f1daaa2091c591323f2ae24d52a28364a1fe/diff /var/lib/docker/overlay2/l/XIHDHF3LIUI2SOI2DELEONWQCJ: no such file or directory

找到以下解决方法，待验证

先以下命令进行查看

sudo du -hs /var/lib/docker/
docker system df
docker system prune
docker system prune -a

再迁移 /var/lib/docker 目录

systemctl stop docker
mkdir -p /home/docker/lib
rsync -avz /var/lib/docker /home/docker/lib/
sudo mkdir -p /etc/systemd/system/docker.service.d/
sudo vi /etc/systemd/system/docker.service.d/devicemapper.conf
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd  --graph=/home/docker/lib/docker
systemctl daemon-reload
 
systemctl restart docker
 
systemctl enable docker
# docker info

显示  

Docker Root Dir: /home/docker/lib/docker

确定容器没问题后删除/var/lib/docker/目录中的文件。