So you can create highly fault tolerant systems with clusters, SAN's etc. But what happens when the building falls down? You really need to have servers that are geographically in seperate locations. It seems to me that SAN's complicate having geographically seperate virtual servers so that if one location is destroyed, the other location picks up for it. So why not just eliminate the SAN and have everything run on clustered servers, with replication to other virtual machines in geographically seperate parts of the world? A SAN seems great when we're just talking about a cluster in one facility with not concern for disaster recovery, but it seems that it complicates things greatly when planning disaster recovery/business continuity. It seems that it would simplify things greatly from a business continouity perspective.