PhysicalDisk counters contain invalid and duplicate entries when you use Microsoft Multipath I/O (MPIO) to control one or more storage devices

Consider the following scenario:

• You connect a computer that is running Windows Vista or Windows Server 2008 to one or more storage devices that are controlled by Microsoft Multipath I/O (MPIO).
• You use a System Monitor tool, such as Performance Monitor (perfmon.exe), to monitor the PhysicalDisk counters of the storage devices.

In the Performance Monitor window, you find that the storage devices are named incorrectly, and that the expected numeric information is not displayed. Additionally, in the Performance Monitor Properties window, the PhysicalDisk counters under the instances tab contain invalid and duplicate disk resource entries. However, when you use the DiskPart.exe tool to check the disk resources, the disk resources are displayed correctly.

This issue occurs because Partition Manager (PartMgr.sys) sends all the redundant path information to Windows Management Instrumentation (WMI).

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 the problem described in this article. 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, your computer must be running one of the following operating systems:

• Windows Vista with Service Pack 1
• Windows Vista with Service Pack 2
• Windows Server 2008
• Windows Server 2008 with Service Pack 2

Restart requirement

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

Registry information

To use one of the hotfixes in this package, 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 notes

• The files that apply to a specific product or milestone (RTM, SPn) can be identified by examining the file version numbers as shown in the following table:
  

  Version	Product	Milestone	Service branch
  6.0.6001.22xxx	Windows Vista SP1 and Windows Server 2008 SP1	SP1	LDR
  6.0.6002.22xxx	Windows Vista SP2 and Windows Server 2008 SP2	SP2	LDR

• Service Pack 1 is integrated into the original release version of Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

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

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

For more information about Diskpart Command-Line Utility , click the following article number to view the article in the Microsoft Knowledge Base: For more information about DiskPart Command-Line Options, visit the following Microsoft Web site:

Additional file information for Windows Server 2008 and for Windows Vista

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

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

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