A Windows Server 2008-based computer that has the MPIO solution installed and that has many LUNs attached stops responding during the startup process after you install hotfix 963702

Applies to: Windows Server 2008 DatacenterWindows Server 2008 EnterpriseWindows Server 2008 Standard


Consider the following scenario:
  • You install a Windows Server 2008 failover cluster on a computer that has the Microsoft Multipath I/O (MPIO) solution installed.
  • Many logical unit numbers (LUNs) are attached to this computer. For example, more than 30 LUNs are attached.
  • Hotfix 963702 is installed on the computer.
In this scenario, Windows Server 2008 may stop responding during the startup process.


The MPIO.sys driver overuses the work item queue in the system. This behavior causes a deadlock situation between a persistent reservation (PR) work item of the cluster and a work item in MPIO.


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.


To apply this hotfix, the computer must run 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 Server 2008 file information note

The MANIFEST files (.manifest) and MUM files (.mum) installed for each environment are
listed separately. 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 (attributes not listed) are signed with a Microsoft digital signature.

Windows Server 2008, x86-based version
File nameFile versionFile sizeDateTimePlatform
Mpio.infNot Applicable3,76012-Feb-200900:51Not Applicable
Windows Server 2008, x64-based version
File nameFile versionFile sizeDateTimePlatform
Mpio.infNot Applicable3,76812-Feb-200900:56Not Applicable

Windows Server 2008, Itanium-based version
File nameFile versionFile sizeDateTimePlatform
Mpio.infNot Applicable3,76411-Feb-200923:50Not Applicable


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

More Information

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional files for all supported x86-based versions of Windows Server 2008
File nameFile versionFile sizeDateTimePlatform
Package_for_kb967724_sc_0~31bf3856ad364e35~x86~~ Applicable1,42112-Feb-200918:31Not Applicable
Package_for_kb967724_sc~31bf3856ad364e35~x86~~ Applicable1,42212-Feb-200918:31Not Applicable
Package_for_kb967724_server_0~31bf3856ad364e35~x86~~ Applicable1,42512-Feb-200918:31Not Applicable
Package_for_kb967724_server~31bf3856ad364e35~x86~~ Applicable1,43012-Feb-200918:31Not Applicable
X86_mpio.inf_31bf3856ad364e35_6.0.6001.22375_none_1d75cf30a8a61bd0.manifestNot Applicable1,65912-Feb-200918:33Not Applicable
Additional files for all supported x64-based versions of Windows Server 2008
File nameFile versionFile sizeDateTimePlatform
Amd64_mpio.inf_31bf3856ad364e35_6.0.6001.22375_none_79946ab461038d06.manifestNot Applicable1,66112-Feb-200918:35Not Applicable
Package_for_kb967724_sc_0~31bf3856ad364e35~amd64~~ Applicable1,42912-Feb-200918:31Not Applicable
Package_for_kb967724_sc~31bf3856ad364e35~amd64~~ Applicable1,43012-Feb-200918:31Not Applicable
Package_for_kb967724_server_0~31bf3856ad364e35~amd64~~ Applicable1,43312-Feb-200918:31Not Applicable
Package_for_kb967724_server~31bf3856ad364e35~amd64~~ Applicable1,43812-Feb-200918:31Not Applicable
Additional files for all supported Itanium-based versions of Windows Server 2008
File nameFile versionFile sizeDateTimePlatform
Ia64_mpio.inf_31bf3856ad364e35_6.0.6001.22375_none_1d777326a8a424cc.manifestNot Applicable1,66012-Feb-200918:31Not Applicable
Package_for_kb967724_sc_0~31bf3856ad364e35~ia64~~ Applicable1,42512-Feb-200918:31Not Applicable
Package_for_kb967724_sc~31bf3856ad364e35~ia64~~ Applicable1,42612-Feb-200918:31Not Applicable
Package_for_kb967724_server_0~31bf3856ad364e35~ia64~~ Applicable1,42912-Feb-200918:31Not Applicable
Package_for_kb967724_server~31bf3856ad364e35~ia64~~ Applicable1,43412-Feb-200918:31Not Applicable