It is just a data drive with user profiles, WSUS database and updates, and a couple program installations..
So the process would be something like:
- power off the vm;
- Edit Settings in vSphere;
- Remove Hard disk 2 (data drive);
- Add new Hard disk, with the target size;
- Power on the vm;
- Copy all guest files back to the data drive.
Should there be a concern about Win2008 freaking out about a new hard drive, or should it be pretty seamless?