I have built my fair share of VMs using both Hyper-V Manager and Virtual Machine Manager 2008 (VMM), but as an engineer, I wanted a way to build multiple VMs without the repetitive clicking involved in doing so within the graphical tools.  Fortunately, Microsoft enabled Hyper-V to be managed through WMI scripting.  With VMM, Microsoft has extended the scripting capability into PowerShell.  For this entry, I will focus on WMI,since I always look to understand what shortcut code is doing behind the scenes.  Much of the PowerShell scripting to accomplish these tasks are shorter than their WMI counterparts, but hide the details that I want to see and understand.

For those that don’t know, WMI is the method used to manage pretty much anything Microsoft has developed that runs under the Windows Operating System, so it is fitting that we can use it to manage Hyper-V as well.  Microsoft has made available several classes in WMI that can be used to manage Hyper-V.  A full listing can be found here.

I will not get into scripting the Hyper-V host server build, but will focus on scripting the virtual machine builds on the host.  See, I am building up VMs all the time and needed a method for lighting them up quickly. Building a host or multiple host servers is nice, but not really what I would use in my scenario.

In Hyper-V, there are four primary components that  make up a virtual machine.  These are virtual disk resources, processor resources, memory resources, and network resources. I will be covering each of these parts separately with a final script that takes everything and merges them into one script that will build a virtual machine for you.

The first thing we need to do before we can play with virtual disks is to create them.  Generally, this is pretty simple with a couple of lines.

$VirtDiskSvc = Get-WmiObject -Class "Msvm_ImageManagementService" -Namespace "root\virtualization" 

$VirtDiskSvc.CreateFixedVirtualHardDisk("f:\VHDs\win2k8.vhd", 20GB)