It sounds intuitive that you may just move the /var/lib/docker dir to another location and symlink it back but it won't work and you'll get an error.
How to move Docker Storage the Correct Way
systemctl stop docker
mv /var/lib/docker /mnt/raid/
Specify the path you want in the data-root parameter eg.
data-data: /mnt/raid/docker
Edit the docker daemonfile.
vi /etc/docker/daemon.json
{
"data-root": "/mnt/raid/docker"
}
Restart Docker and now everything will be working out of the /mnt/raid/docker or whatever you specified in the daemon.json
docker, ioit, intuitive, var, lib, dir, symlink, ll, assumes, mnt, raid, systemctl, mv, edit, daemon, specify, parameter, eg, daemonfile, vi, etc, json, quot, restart, specified,