Originally Posted by speakingtohe
I think the metadata.db file probably has all the metadata in it and is a fairly small file
Best practice AFAIK is to back up the entire library by copying it or archiving it.
Also there is a new backup procedure that creates .opf files qhich I assume are used if your database becomes corrupted
Just as a remark: Backing up only metadata.db and then restoring it after having made changes in the library may (read: will most certainly) result in inconsistencies between the database and the library folders. Best practice, as has been noted, is indeed to backup the entire library.
If memory serves, the discussion I was talking about spawned the OPF backup scheme.