I moved my /var/lib/docker folder to a usb drive and reconfigured my /lib/systemd/system/docker.service to point to the new location.
The docker daemon would not start and I discovered this was because the file system on the usb drive did not support overlays.
So I copied everything back again, and reset the configuration.
Now the deamon starts, but none of my containers or images are appearing in any of the list commands. It's behaving like a new installation.
How can I troubleshoot this further?