The DFS Namespaces service requires a long time to process a "NetDfsAdd" request when a duplicated DFS link exists in Windows Server 2008 R2

Consider the following scenario:

• You install the Distributed File System (DFS) Namespaces service on a computer that is running Windows Server 2008 R2.
• You try to create a new DFS link by using the NetDfsAdd function. An existing DFS link is used as the target for the new DFS link.

In this scenario, the DFS Namespaces service may require a long time to finish the NetDfsAdd request. At the same time, the DFS Namespaces service does not respond to any DFS-related requests.

For example,�the DFS Namespaces service may stop responding for 30 minutes in a large DFS namespace.

This issue occurs because the DFS Namespaces service incorrectly triggers a DFS root synchronization process when a duplicated DFS link exists in the namespace for a new link creation request. However, the DFS root synchronization process is time-consuming in a large DFS namespace. Therefore, the DFS Namespace service stops responding temporarily.

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.

Prerequisites

To apply this hotfix, you must be running Windows Server 2008 R2 and have the DFS Namespaces service installed.

Registry information

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

Restart requirement

You may have to restart the computer after you apply this hotfix.�To avoid a restart, stop the DFS Namespaces service before you install this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

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

• The MANIFEST files (.manifest) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2" section. 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

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

For more information about DFS and the DFS functions, visit the following Microsoft website:For more information about the NetDfsAdd function, visit the following Microsoft website: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

Additional file information

Additional file information for Windows Server 2008 R2

Additional files for all supported x64-based versions of Windows Server 2008 R2