Today I came across this somewhat “classic” error when deploying a new Hyper-V server. When firing up a VM you receive this error message: An error occurred while attempting to start the selected virtual machine(s). In details it says that the hypervisor is not running.

When receiving this error please make sure that…

• Hyper-V server has been powered down and up after adding the Hyper-V role. A simple restart won't be enough.
• Bios settings is correct. This is a sample from an IBM 3650 (Intel proc). Enable “Execute Disable Bit” and enable “Intel Virtualization Technology".

A sample from AMD based proc will follow

More...

Microsoft has released a white paper which compares the different disk type to use in Hyper-V R1 and R2. It covers dynamic VHD disks, fixed size VHD disks and raw devices, and measures performance on different kind of server workloads.

A very interesting white paper – happy reading

http://download.microsoft.com/download/0/7/7/0778C0BB-5281-4390-92CD-EC138A18F2F9/WS08_R2_VHD_Performance_WhitePaper.docx