Srivistava: No, we have our own hypervisor, which we have designed specifically for the design point. We just call it Windows Azure hypervisor, but a lot of the advancements we are making are moving into Hyper-V, [so] the same thing will be available to the on-premises customer. The virtualization support that you get in hardware like NPT and EPT, the nested page tables that are there. We are taking a lot of advantage of that, so that's what [Microsoft engineer] Dave Cutler has done in really optimizing the thing out, so the overhead of the hypervisor is extremely low. And when the hypervisor overhead is low, then we can get maximum utilization by dividing the machine.
InfoWorld: Do you expect people to develop multitenancy apps?
Srivistava: Yes, absolutely.
InfoWorld: Is the framework evolving in that direction to make that easier?
Srivistava: Yes. But my feeling is that we will welcome both, so we don't care. The way we have designed the system is that if a person is developing a multitenancy app, that's fine.
InfoWorld: What features would enable multitenancy on the platform?
Srivistava: The biggest element that you get if you have [multitenancy], because we have multiple tenants that are going on, one is security becomes a very big feature. And so we have multiple levels of security in place. We have VLANs, we put IP filters. And each tenant runs in its own VM in the hypervisor, so we completely go back and isolate each of the tenants out so that they cannot interfere with each other. The second element comes out if a tenant acquires just a fraction of a machine. Each tenant could require different compute powers. We have the power to do that because one tenant can come back and say, "Oh, I only want one-eighth of a machine." One tenant comes back and says, "Hey, I want a whole machine." We can dynamically give him whatever he needs.
Read more about virtualization in InfoWorld's Virtualization Channel.