What is the purpose of full file backups? Why not just incrementals? I’m talking specifically to UrBackup and the way it does things.
I know the differences between full, incremental and differential backups in the traditional sense. And why one might be preferable over another, again, in the traditional sense. But it appears that UrBackup either emulates, or uses directly, the rsync functionality of --link-dest. So for files that are not copied during the incremental, hard links are created to the previous version of those non-copied files. Thus each backup appears as a full backup due to the magic of hard links.
So given this, why do you need to do full file backups? It seems a waste of resources to re-copy files that you already have a copy of. It seems like “incrementals into infinity” would be just fine.
This brings up another question - does UrBackup actually use rsync internally, with rsync’s nice algorithm to only copy the changed parts of files and not the entire file? The behavior of UrBackup seems rsync-like at times, but not completely. For example, UrBackup keeps some kind of database, which rsync does not need to do. But possibly this database is used more for storing configuration and statistics, rather than used to determine which files need to be backed up. I haven’t found any UrBackup documentation that goes into details like this.