Actually... you do not need that fast a network. You can converge state incrementally rather than transfer it in one go. Xen and VMware do this. Surely the cost

Actually... you do not need that fast a network. You can converge state incrementally rather than transfer it in one go. Xen and VMware do this. Surely the cost of a fast SAN and interconnect would quickly outpace the (imho minor) savings from smaller memory allocations.