One of the things that is critical to a virtualisation platform deployment is converting existing physical machines into virtual machines (P2V).  I attempted my first P2V last night and I really saw how much VMM 2008 adds to managing Hyper-V.  A lot of the work was done for me.

VMM 2008 P2V deploys a temporary agent to the physical machine (PM) to perform the conversion.  From what I've heard, this performs a VSS backup of the PM and send the data stream to be rebuilt on the VM.  It works a little like this:

• Deploy disk to your host/cluster.  In a cluster, note down the GUID of the disk being used.
• Find a nice quiet period where you can work on the PM.  I learned this the hard way when doing ESX P2V last year :-)  People can get so mad when their server's CPU and/or disk spike at 100% activity for hours on end ;-)
• Start up the wizard.  You'll need admin credentials for the PM and the name of the PM.
• Configure the VM: disk (you can set the type of VHD and make it bigger if required), CPU, RAM, power up/down and network.
• I leave the network disconnected and the machine set not to automatically power up.  This allows me to leave the PM running while testing the VM.  That's not ideal in all scenarios, e.g. converting a mail or DB server.
• Pick a host.  If using a cluster, ensure that this is the host with the disk you've provided.
• In the disk configuration, ensure that the correct drive is selected.  I found it best to refresh the disk selection dialog if using GUID drives.   Otherwise the last second check would fail.
• Once the check passes, continue with the wizard.
• Now an agent on the PM copies the PM to the new VM.  The VM exists on the cluster at this point ... the job will fail if the VMM service fails or the PM restarts so repeating the wizard will require deleting the VM.  The contents of the VM's disk will get populated over the following hours.

I left that wizard running overnight.  I'll be checking it when I get into work in a few hours.  My opinion so far is that it made managing GUID's easier than bare Hyper-V.  It's still behind Virtual Center because we don't have that single storage made possible by a cluster file system such as VMFS.  However, that will come in Windows Server 2008 R2.