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Consider the following scenario:
You have a Windows Server 2008-based computer.
You expose the computer to a Microsoft Multipath I/O (MPIO)-based pseudo-logical unit number (LUN) that uses the MPIO solution.
You use a Microsoft Device Specific Module (DSM) that plugs into MPIO.
In this scenario, the Windows Server 2008-based computer may stop responding (hang). Additionally, other applications and services that are currently running may stop working.
This problem may occur when one of the following APIs is called:
This problem occurs because the I/O requests are stopped at the MPIO level. A computer that uses a pseudo-LUN remains in a throttled state and cannot return. This behavior causes all I/O requests that use the pseudo-LUN to stop.
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.
Note Because MPIO is not supported in Windows Vista, this hotfix is only for Windows Server 2008. Although the hotfix packages are marked for Windows Vista on the "Hotfix Request" page, they are for Windows Server 2008.
No prerequisites are required.
You must restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace any other hotfixes.
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 notes
The MANIFEST files (.manifest) and MUM files (.mum) that are installed for each environment are listed separately. MUM and MANIFEST files and their associated security catalog (.cat) files are critical to maintaining the state of the updated component. The security catalog files are signed with a Microsoft digital signature. (The attributes for these files are not listed.)
All supported x86-based versions of Windows Server 2008
All supported x64-based versions of Windows Server 2008
All supported IA-64-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.
Additional file information for Windows Server 2008
Additional files for all supported x86-based versions of Windows Server 2008
Windows Server 2008 Standard, Windows Server 2008 Enterprise, Windows Server 2008 Datacenter, Windows Server 2008 Standard without Hyper-V, Windows Server 2008 Enterprise without Hyper-V, Windows Server 2008 Datacenter without Hyper-V, Windows Server 2008 for Itanium-Based Systems