You install some high-performance storage devices on a computer that is running Windows Server 2008 R2.
For example, you install a host-based RAID adapter or a Fibre Channel adapter that can access more than 4 gigabytes (GB) on a computer that is running Windows Server 2008 R2.
The Storport.sys driver is used to manage these storage devices.
The computer has more than 4 GB of physical memory.
You install an application or service that uses a large amount of memory on the computer.
For example, you install SQL Server or Exchange Server on the computer.
In this scenario, the computer may intermittently perform poorly or stop responding for a while.
For example, the computer stops responding for 10-20 seconds.
This issue is caused by an incorrect memory allocation limitation in the Storport.sys driver. The Storport driver (Storport.sys) requires memory within 4 GB of computer memory for its own allocations and for implementing the miniport IOCTL that is used by storage configuration and by management utilities. Therefore, the driver unnecessary creates contention for memory within 4 GB of computer memory.
When little or no memory within 4GB of computer memory is available, the memory manager tries to trim the working sets of all processes for free memory. Therefore, the issue that is described in the "Symptoms" section occurs.
Note This hotfix is for use with Storport.sys miniport drivers that support full 64 bit physical addressing. We recommend that end-users that encounter this issue contact their miniport driver vendor to ensure the miniport driver takes advantage of the Windows changes first. You can apply this hotfix by using instructions from the miniport driver vendor.
To resolve this issue, follow these steps:
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
1. Install this hotfix on the affected computers that are running Windows Server 2008 R2.
2. Create a registry entry under the Storport miniport driver. To do this, follow these steps:
Click Start, type regedit in the Start Search box, and then press ENTER.
Locate and then click the following registry subkey:
Note<MINIPORT> means the name of the Storport miniport driver.
On the Edit menu, point to New, and then click DWORD Value.
Type Supports64BitAddressing, and then press ENTER.
Right-click Supports64BitAddressing, and then click Modify.
In the Value data box, type a nonzero value.
Exit Registry Editor.
Note After you follow these steps, the miniport drivers that uses the Storport.sys driver can access more than 4 GB of physical memory.
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.
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, submit a request to 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.
To apply this hotfix, you must be running one of the following operating systems:
Windows Server 2008 R2
Windows Server 2008 R2 Service Pack 1 (SP1)
For more information about how to obtain a Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:
976932 Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2
You must restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace a previously released hotfix.
The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
6.1.760 0. 20xxx
Windows Server 2008 R2
6.1.760 1. 21xxx
Windows Server 2008 R2
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 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows Server 2008 R2
For all supported IA-64-based versions of Windows Server 2008 R2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, 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 file information
Additional file information for Windows Server 2008 R2
Additional files for all supported x64-based versions of Windows Server 2008 R2