DevLink Hyper-V session Questions and Answers

I had the pleasure and speaking at DevLink in Nashville on Aug. 5th and 6th last week.  There were some good questions on Hyper-V that came up and here they are with the answers.

Q: What is a reboot need when the hardware virtualization is turned on in the BIOS?
A:
Hardware-assisted virtualization is a virtualization approach the leverages the hardware capabilities, primarily from the host processors on the host systems. Typically, this not enabled by default, and since it is at the processor level, turning this on in the BIOS will require a hard reboot, to enable the capability.

Q: What is the overheard for the hyper-V server role?
A:
As with any server virtualization software, there is a certain amount of overhead associated with running the virtualization code required to support guest operating systems running on Hyper-V. So it really depends on what workloads you are performing on the server, you will need to look at several factors including

  • CPU Overhead
  • Memory Overhead
  • Network Overhead
  • Disk Overhead

Q:What is the minimum requirements for the hyper-v host?
A:
In addition to the system requirements for Windows Server 2008 R2 as described in the release notes, a 64-bit system with hardware-assisted virtualization enabled and data execution prevention (DEP) is required. It is also recommended to ensure that you have a clean install of x64 edition of Windows Server 2008 R2 to be able to use the Hyper-V technology.

Q: What happens when you put a box to sleep?
A:
When you enable hyper-v you lost the capabilities for sleep and hibernation, here is a good post on the subject: https://blogs.technet.com/b/doxley/archive/2008/09/05/getting-some-sleep.aspx

Q: Are the virtual HD that are available from Microsoft online time bombed or how is the licensing handled?
A:
Open evaluations for customers will enable a 30-day evaluation time period for a VHD running on Windows Server 2003 and a 60-day evaluation time period for a VHD running on Windows Server 2008.