Virtual Machine Management : Performance

Rapid Provisioning in VMM 2008 R2 using the UseLocalVirtualHardDisks and SkipInstallVirtualizationGuestServices flags

mlmich — Thu, 07 May 2009 13:46:00 GMT

At MMS 2009, our team announced a new feature of VMM 2008 R2 called Rapid Provisioning. This feature is not available in VMM 2008 R2 beta, but it will be available in the upcoming release candidate and in the RTM version. This feature was implemented...(read more)

Issues with adding a host to VMM when the computer has more than 16 processors

mlmich — Mon, 09 Feb 2009 19:58:00 GMT

It has come to our attention that trying to add a computer with more than 16 processors (for example a quad six-core machine with 24 processors) is crashing the VMM server with the following exception:

System.InvalidOperationException: Nullable object must have a value.

at System.Nullable`1.get_Value()

at Microsoft.VirtualManager.Engine.Adhc.WindowsHostDataProperties.GetProcessorData()

at Microsoft.VirtualManager.Engine.Adhc.WindowsHostDataProperties.PopulateProperties()

From a Hyper-V perspective we support up to 24 cores (requires a QFE http://blogs.msdn.com/taylorb/archive/2008/09/23/24-core-support-for-hyper-v-hosts.aspx). We have a few workarounds for VMM to work in this case (either do #1 or implement #2 and #3):

You can limit the number of CPUs via msconfig to 16 (we know this solution is not ideal in this case, but wanted to document it anyway)
Go to BIOS, then navigate to Advanced Setup>Clustering Mode and set it to Physical (default is Logical)
Use Bcdedit to add USEPHYSICALDESTINATION and set to YES. This forces the physical APIC to be used.

cheers.

How to enable server-optimized garbage collector for VMM

mlmich — Wed, 04 Feb 2009 19:38:00 GMT

If your VMM implementation has over 150 hosts, we strongly recommended that you enable server-optimized garbage collector (GC) on the VMM server instead of the default workstation garbage collector. This can significantly reduce the CPU utilization on the VMM server and improve your performance for parallel VMM operations.

To accomplish this, simply create a new filed named vmmservice.exe.config and place this file in the same location as vmmservice.exe (VMMservice.exe is located in the bin directory of the VMM server role installation)

This file should have in it the following information (bold and indented). If you want to know more about this option, read this link: http://go.microsoft.com/fwlink/?LinkId=102219

<configuration
   <runtime>
      <gcServer enabled="true"/>
   </runtime>
</configuration>