In installing Longhorn and Avalon CTP on Virtual PC 2004, I've learned some lessons that I'd like to share with you:
- Don't use differencing virtual hard disks for something you project to be rather big. I have a "base" Windows XP SP2 virtual machine and hard disk, so that whenever I want to try out some new (and possibly instable) program, I create a new temporary virtual machine with a differencing virtual hard disk off the base WindowsXP one. This is fine for temporary and small programs, but when I installed Avalon CTP + Whidbey, the differencing hard disk was about 3.6 GB big, which is almost the same size as the Windows XP base and the guest OS ran really slow. Instead, just make a physical copy of the base virtual machine and hard disk, rename them if needed, and then take it from there. After doing that, my WindowsXP + Avalon CTP + Whidbey was "only" 4.2 GB big and ran significantly faster.
- Shut down the guest OS when you transfer the OS to another machine. The other day, I copied my running 4 GB Longhorn OS from my work computer to my personal laptop over the internet using VPN. After spending an entire day for the VPN copy to complete, I couldn't start the Longhorn instance on my laptop because I didn't have enough virtual memory there. Unfortunately, you can't change the memory allocation while the guest OS is still running. I even tried changing the memory allocation in the .vhd file (since it's really just an XML file), but I was still not able to start the instance (not to mention how the guest OS is going to like that). Anyhow, I end up going back to my work computer to shut down the Longhorn OS and then transfer it again.
- Install Virtual Machine Additions ASAP. I was aware that installing Virtual Machine Additions will make the guest OS run much faster and support the mouse much better. However, I was not aware that it is also the requirement to run Longhorn 4074 in color. When I first installed Longhorn on my Virtual PC, I was not able to have it run in color. I tried to fixed this problem first, before I installed anything else, so I tried installing various graphics drivers on Longhorn and playing with the display settings to no avail. Only after installing the Virtual Machine Additions, Longhorn would start in color.
- The eraser trick on Robert Memoir's great Virtual PC website doesn't do it for me. After doing all that work, my virtual hard disk would be even bigger than it was before. Don't know if I am doing something wrong, but maybe you guys have more luck than me. I'll have to try the pre-compactor tool when I get a chance.
- Ben Armstrong has a great tip on how to use Virtual PC for computer migration