I have just completed a migration from SBS 2003 as a physical server to SBS 2011 as a Virtual Server running on Microsoft Hyper-V and the entire process went without a hitch.
As usual, the article that I followed was Demazter’s excellent migration article.
I did have some fun working out how to create and load up the SBS migration file needed on the SBS 2011 server to tell the installation that it is a migration, not a clean install. After some head scratching, I created a Virtual Floppy Disk file, loaded it onto an existing Virtual Server, copied the SBS Answer File to the Virtual Floppy Disk, dismounted it, re-configured the SBS 2011 Virtual Server to also load the Virtual Floppy Disk and that was ll that was needed.
Again, the entire process took 3 days – which so far every other migration I have performed has taken. The longest / slowest part is the migration of Exchange Mailboxes and data, but once that is done, the rest is much quicker.
So, if you are wondering if you can migrate to SBS 2011 in a Virtual Server environment, I can happily confirm that it can.