We seem to end up buying a new NAS system every year or so, as the old one get fulls, so we start again, moving what we need to keep going with, leaving the old stuff on the old drives, so there's a kind of archive going on - the more time passes the more drives we have, which are then getting backed up too - it's not a clean system as lots of stuff is getting backed up to Amazon Clour multiples time along with stuff we def no longer need.