The DFS service may consume many of the CPU and memory resources on a Windows Server 2003-based domain controller

On a Microsoft Windows Server 2003-based domain controller that has Distributed File System (DFS) site costing enabled, the DFS service may consume many of the CPU and memory resources. Additionally, the client computers may take a long time to log on to the domain.

The problem occurs when the client referral request workload becomes too large. The probability that the problem will occur relates directly to the number of sites in the Active Directory directory service forest.

This problem occurs because DFS site cost lookups of client referral requests do not correctly release references. This behavior leads to redundant cache entry copies and excess memory use. The high CPU use is caused by lookups in oversized cache lists.

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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 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.

Prerequisites

There are no prerequisites.

Restart requirement

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 tool in Control Panel.

Windows Server 2003, x86-based versions

Windows Server 2003, Itanium-based versions

To temporarily resolve this problem, restart the DFS service on the affected domain controller. You can also disable site costing at the DFS root. If multiple namespaces (roots) are configured, referral activity for a particular root should closely match excess memory and CPU usage.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was corrected in Microsoft Windows Server 2003 Service Pack 1.