移动docker目录时报错。
root@ubuntu:/var/lib# mv docker/* /data/lib/docker
mv: 无法进行跨设备的移动：'docker/containers' 至'/data/lib/docker/containers'；无法删除目标: 目录非空
mv: 无法进行跨设备的移动：'docker/overlay2' 至'/data/lib/docker/overlay2'；无法删除目标: 目录非空
root@ubuntu:/var/lib# cat /proc/mounts|grep containers #查看容器挂载情况
shm /var/lib/docker/containers/6749d2cc3d19e956905a39fc0b2bacad177e648158f5b0dd8585e793d9b8ec5c/mounts/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=1048576k 0 0
shm /var/lib/docker/containers/3989c6dbfc8720b0c5a23e66ce2c164f830a55f8a85cfea79c2d23a64e687e5a/mounts/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=1048576k 0 0
root@ubuntu234:/var/lib# df -h #查看挂载情况
文件系统 容量 已用 可用 已用% 挂载点
/dev/sdb2 228G 193G 24G 90% /
/dev/sda 3.6T 2.6T 890G 75% /data
overlay 228G 193G 24G 90% /var/lib/docker/overlay2/6f469b0e5ee5aa80ad323dbf710518308e3cd710b78a207fcd5c7073f9b1987c/merged
shm 1.0G 0 1.0G 0% /var/lib/docker/containers/3989c6dbfc8720b0c5a23e66ce2c164f830a55f8a85cfea79c2d23a64e687e5a/mounts/shm
tmpfs 6.3G 0 6.3G 0% /run/user/1000
tmpfs 6.3G 0 6.3G 0% /run/user/0
卸载容器：
root@ubuntu234:/var/lib# umount /var/lib/docker/overlay2/6f469b0e5ee5aa80ad323dbf710518308e3cd710b78a207fcd5c7073f9b1987c/merged
root@ubuntu234:/var/lib# umount /var/lib/docker/containers/3989c6dbfc8720b0c5a23e66ce2c164f830a55f8a85cfea79c2d23a64e687e5a/mounts/shm
再次执行mv命令，无报错：
root@ubuntu:/var/lib# mv docker/* /data/lib/docker