I've been using Microsofts Hyper-V software for the last month and I gotta say I'm impressed.
At work, we've setup box with 1 Terrabyte of Hard Drive Space (Raid 10), 16GB of RAM and two Quad Core Xeons running Windows Server 2008 x64 and Hypervisor. This is being used for our Test and User Acceptance platform - allow us to create our environments very rapidly (with some help from Sys Prep) and performance is amazing considering we are running 10 VPC's, some even running Biztalk + SQL server instances inside the virtuals as well. I have not yet seen even a hint of any drop in performance and still plenty of room for expansion with this hardware.
The difference between Hyper-V and other Microsoft Virtual technolgies is that the Windows 2008 OS actually allows Hyper-V to sit a hell of a lot closer to the metal (i.e. less layers between the Virtual and the Physical hardware) while still doing a great job of distributing the load of the VPC's accross the machine. It totally rocks compared to Virtual PC Server - it isn't even close to Hyper-V on performance.
It has definately development lives much easier, being able to spin up a new Syspreped OS, drop it on, hook it up to the network and then install whatever we need. The other thing we've been able to do is to port physical machines to virtual (this comes as an easy step by step wizard) - although I have come across some issues and couldn't get some machines to move accross so easily, but this has let us move our current enviroments on seperate physical machines quickly into the virtual fold. I was further impressed in most cases that you can port a machine from physical to virtual while the physical machine your porting is still online.
Just some things to note if you are interested when using the release candidate...
1. It only runs on Windows Server x64 OS, no other OS is supported.
2. It's currently only at a Release Candidate.
3. Although Windows 2008 Server x64 contains the Integration Services components that are required for it be a guest, these are only compatible with Beta 2 of Hyper-V - When using the release candidate you will need to install a patch in the guest OS to allow these drivers to install correctly (See http://support.microsoft.com/kb/949219).
4. When migrating from a previous Virtual PC VHD to Hyper-V, it may not detect the VMBUS and other things correctly, leaving you without some of the comforts of the Integration Services compents. In order to fix this, use Start-->Run MSCONFIG-->Boot Tab-->Advanced Options and Click Detect HAL and reboot.
5. Also when migrating a previous Virtual PC VHD to Hyper-V, if you can't initally get any network access in the Hyper-V admin tool, set the Virtual PC up so it's using a Legacy network driver - this should fix it.
6. If you are stuck wondering why you can't log into the Hyper-V Adminstration tool, you'll need to get the user that original installed Hyper-V on the machine to log into it first and add you as an Administrator before you can use it yourself.
Anyway, check out this for more info
http://www.microsoft.com/windowsserver2008/en/us/virtualization-consolidation.aspx
Cheers
Matt
