We want to buy 2 new servers and load them up with processing power and ram and then migrate our current physical machines (we have 15 physical servers and 4 virtual using hyper-v) to virtual using hyper-v. I would like to know if it would be a good idea to have all our vms on one live host and then have the other offline host as a mirror image of the first host with real-time replication from the online host to the offline. We are also thinking to use the internal host server hard drives as storage instead of an external SAN. Are there any drawbacks to this? Would there be a better or more efficient way to go about this and why?