I’ve been trying (unsuccessfully) to find an answer. Can anyone point me to some instructions on how to move a lemmy instance to another server?
Is it just a matter of copying the volumes and conf files to the new server and doing a docker compose pull & up from that new location?
If you’re taking that approach make sure you shut down the stack before you copy the data over so everything gets copied over consistently (e.g. the DB isn’t in the middle of a write), and yes it should pretty much be that easy.
Is there a better approach?
No, these issues are pretty much by-design. In ActivityPub IDs are inherently tied to the domain on which they were created. Based on the nature of federation it is safe to assume someone somewhere will still go looking for that thing via the outdated URL.
Use rsync to get the bulk of the data over (even if it’s mid write) one or more times, then stop the stack on the origin server, and run rsync again. It should be much faster.