Rescue containers from old OS drive?

I recently had my OS drive die, and with it, my containers. Now they were all backed up, except one which had an “EOF” error when I tried to restore it. So I’ve been able to access my old OS drive and most of the data is intact (I guess only some necessary boot files actually got corrupted, but the reallocated sector count is climbing very quickly, so new drive.) Do I only need to copy the data from /mnt/@/var/snap/lxd/common/lxd/containers/mycontainer to my current system or is there more I’ll need to make it work?

Depends on your storage backend, but in general, yes, copying that path across should be enough to then let you run lxd import mycontainer which will have LXD recreate the needed database records.