Yesterday while presenting at TechDays08 in Ottawa I was a panel expert for the Virtualization Chalk Talk. An interesting question which came out of that session as prevalent was, what is the stance on virtualizing SQL Server?
In the case of SQL 2005, I will speak about my experience in consulting. I do a lot of consulting with Operations Manager and use SQL Server 2005 as the back end database.
I do not recommend that customers virtualize SQL if it can be prevented. The bottleneck is typically memory when virtualization is used. Other than specifying how much memory a VM uses at creation, there is no way to reserve RAM only for a specific VM currently and that seems to be a problem.
New with Hyper-V there is the ability to use pass-through disks with your virtual servers to make use of the actual physical hardware resources...
Have a look at this webcast from TechNet Edge on virtualizing SQL Server 2008, it is insightful:
http://edge.technet.com/Media/SQL-Server-Virtualization/
For great, in-depth, technical training on System Center, check out www.infrontconsulting.com/events.htm.