MSDTC Outages Will Affect Cluster Group

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2006-03-16

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether you have configured a failure of the Microsoft Distributed Transaction Coordinator (MSDTC) resource to affect the group:


If the value of ClusterMSDTCInstance is 2, the Exchange Server Analyzer displays a warning.

The MSDTC resource must be present in an Exchange cluster to support initial installation and service pack upgrades. However, it is not required while Exchange is running.

By default, a failure to the MSDTC resource will affect the group. Two examples of resource failure are as follows:

  • The log file size exceeds the capacity of the disk.

  • The physical disk for the MSDTC resource fails.

Specifically, a failure to the MSDTC resource will cause a failover of all Exchange services that are running on that cluster node to a different node in the cluster. However, because the MSDTC resource is not a required resource, it does not have to be configured to affect the group.

To resolve this warning, configure the Exchange Cluster so that a failure to the MSDTC resource does not affect the group.

To configure Exchange so that a failure to the MSDTC resource does not affect the group

  1. Log on to any node of the cluster.

  2. Click Start, point to All Programs, point to Administrative Tools, and then click Cluster Administrator.

  3. Under Groups, right-click the cluster group that includes the MSDTC resource.

  4. Right-click the MSDTC resource, and then click Properties.

  5. On the Advanced tab, clear the Affect the group check box, and then click OK.

For More Information

For specific steps about how to create an MSDTC resource, see "How to Install the Microsoft Distributed Transaction Coordinator in a Windows Server 2003 Server Cluster" in "Deploying Exchange Server 2003 in a Cluster" in the Exchange Server 2003 Deployment Guide (

For more information about MSDTC and Exchange, see "Cluster Groups" in "Understanding Exchange Server 2003 Clustering" in the Exchange Server 2003 High Availability Guide (

For more information about how to add the MSDTC resource in Microsoft Windows Server™ 2003, see Microsoft Knowledge Base article 301600, "How to Configure Microsoft Distributed Transaction Coordinator on a Windows Server 2003 Cluster" (


Knowledge Base article 301600 includes a reference to article 817064, "How to enable network DTC access in Windows Server 2003" ( It is an Exchange Server security best practice not to enable network DTC access for an Exchange cluster. If you are configuring the Distributed Transaction Coordinator resource for an Exchange cluster, do not enable network DTC access.