Originally Posted by
Moonsorow
Sure. Its a little hard to explain. Hyper-V along with VMWare, and Citrix Xen are virtual tools. What this allows is to create "virtual" servers using a physical infrastructure. Take for example, right now if you want to have a server in your house you can do one of a few things. One you can build a server, or you can use your home PC that you use to play WoW on and create that same server virtually.
Advancement to a business who uses mission critical data and storage (private cloud based storage using NetApp or EMC). Instead of buying 200 physical servers, the company buys 20 physical servers and then virtual's the other servers. With this, this allows all the users to still connect and see the data, but it's done in a virtual machine environment, with no physical servers.
A lot of companies (small to big) do this where they consolidate the physical machines for virtual machines. There are many reasons to do this, one your carbon footprint is a lot smaller, and two you save thousands on hardware, licenses, and electricity.
What BioWare did was have 500 physical servers across the United States (I'm not sure on the numbers of Europe). With those physical servers they created 3x more using Hyper-V for virtual machines. That would mean there was 1500 servers, but you would never see that. You would see a "server name" in a game, but on the inside of it you would've seen something called server clustering where it allows one server to have many connected to each other and act as one. Virtual Private Servers (VPS) are known to do this for everything including music to movies, to hosting games, and many other things. This is how iTunes Match works as well as Google Play and even Facebook and Twitter.
The thing about using Virtual Machines is they suck up a lot of memory, hard drive space and processing power. Now memory is ever extendable and most big companies will easily have 100+GB of memory in their servers to run their data. Datacenters have this as well. Hard Drive space is also ever extendable by providing fast speed to the drives using a fiber connection called a SAN (Storage Area Network) or using a NAS (Network Attached Storage) if your using CAT5 / CAT6. Processing power on the other hand is limited by what Intel and AMD supply the company with. Right now the power isn't there to make a full game run in a virtual infrastructure.
The problem is you have Hyper-V which is probably the worst server VM around. Don't get me wrong, I use it for a lot of things, but never the scale of an MMO. Though I'm more of a fan of VMWare Virtualcenter which has better infrastructure management including affinity rules for your processor, memory, and hard drive. Hyper-V uses a more dynamic system which is fine for companies who really don't want to do a lot of micromanaging. The micromanaging of Virtualcenter makes it the best as you can min / max everything and get the best results. Its like using Robot for everything in WoW.
Blizzard on the other hand has many servers linked to one actual server. Again this goes back to clustering, and instead of VM they host all the servers themselves. Each server is used for something different, as one can be used for PVP, the other used for Raids, and so on. The database that they have controls all those aspects of those servers. Without the database all that data would be scattered around and would look like a absolute chaos.