With SQL Server 2008 RC0 available for download now, people are asking about Hyper-V versus Virtual PC and Virtual Server. For best performance, I recommend that you build a Hyper-V virtual machine. This raises a question about convenience. What if you have existing Virtual PC or Virtual Server virtual machines and want to migrate them to Hyper-V? It's easy if you understand what is required.
You must remove the Virtual Machine Additions before you use your Virtual PC or Virtual Server vhd as the basis of a Hyper-V virtual machine. You also must have the virtual machine at the correct service pack level to take advantage of the performance optimizations Hyper-V Integration Services provide. (People have already posted about confusing SSIS and Hyper-V when only the words "Integration Services" are used.)
Currently in Hyper-V RC1, these are the only Windows operating systems and patch levels that can take advantage of Integration Services (subject to change at RTM):
- XP Service Pack 3
- 2003 Service Pack 2
- Vista Service Pack 1
- Windows 2008
To avoid a Catch-22, you should install any required service pack in Virtual PC or Virtual Server before uninstalling the Virtual Machine Additions. If you uninstall the Additions before installing the service pack, installation of the service pack will take longer. If you install the service pack after switching to Hyper-V, you won't have mouse control until you've installed Integration Services, which requires that the service pack already be applied.
Keep in mind that Hyper-V RC0 Integration Services worked only with Windows 2003 and 2008. RC1 added XP and Vista. RTM might support more operating systems and service pack levels.