It is problematic that backups are an all or nothing proposition - we really need to be able to backup by "Categories" .  We are really struggling with this issue.   For example, we want to archive our spring 2010 category (489 courses).   To do that we need to turn backups on for all courses on our Moodle, download all 7,851 course and identify which ones are the 489 spring courses and which ones failed to backup properly.