Today we released a fix for to resolve an issue that can lead to guest VM’s crashing after a live migration. This issue only impacted virtual machines that where utilizing virtual SCSI controllers and was only seen under some specific stress conditions however if you have VM’s with SCSI controllers and utilize live migration than I would recommend investigating and installing this hotfix.
http://support.microsoft.com/kb/2636573
Article ID: 2636573 - Last Review: January 10, 2012 - Revision: 1.0
FIX: The guest operating system may crash when you perform a live migration of Hyper-V virtual machines in a Windows Server 2008 R2 environmentSymptoms
In a Windows Server 2008 R2 environment, you perform a live migration of Hyper-V virtual machines. In this scenario, the guest operating system may crash. Additionally, you receive a Stop error message that resembles the following:
STOP 0x000000D1 (parameter1, parameter2, parameter3, parameter4)
DRIVER_IRQL_NOT_LESS_OR_EQUAL
To resolve this problem, install this update on the host computer where the Hyper-V virtual machines are located.
Update information To resolve this problem, install this update from Microsoft Windows Update (http://update.microsoft.com) .Download the update package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=06c9e6e0-26de-44dc-a2e7-6a87fe0d5e76)
Release Date: January 10, 2012
For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 (http://support.microsoft.com/kb/119591/ ) How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
Prerequisites To apply this hotfix, you must be running Windows Server 2008 R2 Service Pack 1 (SP1).976932 (http://support.microsoft.com/kb/976932/ ) Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2
Registry information To use the hotfix in this package, you do not have to make any changes to the registry. Restart informationYou must restart the computer after you apply this hotfix.
Taylor Brown
Hyper-V Enterprise Deployment Team
taylorb@microsoft.com
http://blogs.msdn.com/taylorb