Hello,
My laptop permanently broke down, hard disc safe. I was using devicemapper as the storage engine with Docker version v1.10 installed from the Fedora 23 repositories. New laptop set up with Docker v1.12 from the Docker repositories on Fedora 24, using the overlay2 storage engine.
A lot of the data were set up as external volumes that I was managing, so these would be easy to migrate. I copy the volumes directory from the old disc to the new one and I mount them on new containers that run the same image. Works fine so far.
I have some files though that I need that were not part of a volume. What would be the best way to extract those? A possible solution seems to be running the docker daemon (using the new laptop) pointing to the old docker directory in the old disc, with the devicemapper storage engine, and export the containers as tar archives with the ‘docker export’ command. Then stop the docker daemon, restart it with the new setup (new docker directory, overlay2 storage engine), and import the exported archives as containers.
I wanted to check if anybody has tried something similar, having the following main concern: As long as I use the correct storage engine with the correct docker directory, is there clean isolation between docker runs e.g. I shouldn’t expect anything to get messed up in the new installation when switching back and forth, right?