I have a small business with a couple of mac minis, 1 is mac mini server, and several winxp systems. What is, or is there, a solution to backup both win and mac? Before I added the 2 macs, I backed up to an external drive attached to the old win server and also a NAS drive that was in another building on our campus. They backed up differentially everynight two both drives. So if I had a fire in one location, I had a backup in the other. Is there such a solution, or do I have to have 4 different external drives? 2 for macs and 2 for win.