I set up a few templates over the last few evenings, Windows 2008, Vista and Windows 2003. I sysprepped them today and exported the VM’s. I’ve noticed some funnies in the exports – the confix.xml retains the path to the VHD of the original machine. This cause some problems when I copied the exports and re-imported them as new machines.
My lab machine has only so much disk and I’ve way more testing that I need to do. I decided to use the VHD’s of my sysprepped templates as parents for differencing disks. These differencing disks are what my VM’s use. The idea is that the child disk stores on the differences between the VM that I run and the parent disk of the template.
I deployed them like this:
- I created a template VM, sysprepped it and saved exported it.
- I put the exported VHD somewhere safe.
- I created a new VM but did not create a disk in the wizard.
- I returned to the settings of the VM started creating a new disk.
- The new differencing VHD was stored in the Virtual Hard Disks folder of the new VM. It’s parent was the VHD of the exported template.
- The new VM is powered up and runs the mini-setup wizard, i.e. I name the machine.
Simple and diskspace economic. I can deploy more VM’s and they core OS is stored only once. It’s perfect for a lab. Obviously it’s going to be slower if running plenty of VM’s off the parent. You wouldn’t do this for production but it’s fine for a lab.