Currently /var/lib contains data for system utilities (dpkg, apt, aptitute) and for user application like databases. What about moving default location for applications to /export ? Think about "modern fs" like btrfs and zfs: One may want to create a snapshot of the entire system, user data should not get into such a snapshot, but, of course, /usr along with dpkg database - should. Again, the idea is to move all user data away from /var/lib