Error message when you try to start a Hyper-V virtual machine on a Windows Server 2008-based or Windows Vista-based computer that uses the NUMA architecture: "An error occurred while attempting to change the state of virtual machine VMNAME"

You are running a Windows Server 2008-based or a Windows Vista-based computer that uses the non-uniform memory access (NUMA) architecture. When you try to start a Hyper-V virtual machine, the operation may fail because of a memory allocation issue. Additionally, you may receive the following error message: This issue occurs even when there is sufficient memory available.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the �Hotfix Request� page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

To apply this hotfix, the computer must run one of the following operating systems:

• Windows Vista SP1
• Windows Server 2008

Restart requirement

You have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other previously released hotfixes.

Registry information

To use this hotfix, you do not have to make any changes to the registry.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Vista and Windows Server 2008 file information note

The .manifest files and the .mum files that are installed in each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. These files and their associated .cat (security catalog) files are critical to maintaining the state of the updated component. The .cat files are signed with a Microsoft digital signature. The attributes of these security files are not listed.

For all supported x86-based versions of Windows Server 2008 and Windows Vista

For all supported x64-based versions of Windows Server 2008 and Windows Vista

For all supported Itanium-based versions of Windows Server 2008

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

The traditional model for multiprocessor support is symmetric multiprocessor (SMP). In this model, each processor has equal access to memory and I/O. As more processors are added, the processor bus becomes a limitation for system performance.

System designers now use non-uniform memory access (NUMA) to increase processor speed without increasing the load on the processor bus.

For more information about NUMA support, visit the following Microsoft Web site: For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Additional file information for Windows Server 2008 and Windows Vista

Additional files for all supported x86-based versions of Windows Server 2008 and Windows Vista

Additional files for all supported x64-based versions of Windows Server 2008 and Windows Vista

Additional files for all supported Itanium-based versions of Windows Server 2008