XGEN: The Microsoft Support Policy for an Exchange Failover Cluster

This article describes the Microsoft support policy for Exchange Server if it is installed on a failover cluster.

Microsoft Product Support Services (PSS) supports Exchange Server failover clustering that is based on the failover clustering features of the Microsoft Cluster Service that is provided with the Microsoft Windows NT 4.0 or the Microsoft Windows 2000 operating systems, if those operating systems are installed on "server clusters" that are listed on the Cluster Hardware Compatibility List (HCL). "Server clusters" means computers that run the Microsoft Cluster Service (MSCS), not the Network Load Balancing or the Windows Load Balancing Service. Supported Exchange Server failover clustering installations must also follow the Microsoft support policy for server clusters and the Hardware Compatibility List. For additional information about the Microsoft support policy for server clusters and the HCL, click the following article number to view the article in the Microsoft Knowledge Base: If you configure Exchange Server with clustering products other than the Microsoft Cluster Service, you must contact the third-party provider of those products for support issues that are related to the Exchange Server installation.

Exchange Server Failover Clustering for Clusters That Are Not Listed on the HCL in the Cluster Category

If your Exchange Server failover cluster solution is not listed on the HCL in the Cluster category, the cluster solution is unsupported. However, Microsoft PSS offers troubleshooting information on request. Microsoft PSS does not guarantee that a resolution can be found for non-HCL clusters.

For support issues, follow these steps:

1. Before you start any troubleshooting steps, contact the Original Equipment Manufacturer (OEM) to discuss whether your particular cluster implementation is supportable. The OEM can best answer configuration and supportability questions about the cluster hardware devices.
2. After agreement that no solution is guaranteed, and that no incident refund will be provided, Microsoft PSS will troubleshoot the issue. If it is not agreed that a solution to the issue is not guaranteed, PSS will not troubleshoot the issue and will refund the incident.
   
   Important Microsoft does not guarantee that a solution can be provided with non-HCL clusters. If no resolution is found through troubleshooting the issue, the incident will not be refunded.
3. Microsoft PSS will use standard troubleshooting procedures to try to isolate the server cluster issue. Some typical troubleshooting methods that PSS uses include:
   • The use of the Microsoft Knowledge Base. The Microsoft Knowledge Base is available to customers through Microsoft TechNet, or you can visit the following Microsoft Web site:
     http://support.microsoft.com
   • Determining whether the problem can be reproduced on supported cluster installations (where possible).
     
     Note If the cluster is not certified, there is no hotfix support available because PSS cannot determine if the problem is caused by hardware incompatibility or by software behavior such as a bug.
4. If PSS cannot resolve the problem, PSS may recommend some constructive alternatives or workarounds, which may include the following:
   • Requesting that you try to reproduce the problem on a cluster that is listed on the Cluster HCL.
   • Recommending that you use a cluster solution that is listed on the Cluster HCL.
   • Requesting that you work with the OEM to have the cluster solution listed on the Cluster HCL.
   • Recommending that you work with the OEM for a solution or workaround to the problem.

The hardware specifications for server clusters are extremely stringent. The Cluster HCL contains a list of known acceptable cluster configurations that have been tested. Many of the cluster issues that occur with Exchange Server on a failover cluster are caused by the cluster hardware devices that are used.

Some examples of hardware incompatibilities that can cause cluster problems include the following:

• The cluster solution does not properly isolate the shared disk and host bus adapters (HBAs) from other devices on the shared bus.
• The HBA does not properly handle reservations, or release or renew a device on the shared bus.
• The network adapters for intra-cluster communication have too high a latency.
• The PCI bus is incorrectly configured and has incorrect adapters in the wrong bus (primary, secondary, tertiary).
• The SCSI controller does not deploy proper termination.

Although this list does not include all of the issues that can cause issues with a server cluster, none of the issues that are listed can be detected by PSS. All of the preceding issues would typically be discovered if the complete cluster solution were tested for Cluster HCL compatibility.

If a complete cluster configuration is listed for an earlier operating system but is not listed for the newer operating system that you are using, support as documented in this section will be provided.

To view the Microsoft Hardware Compatibility List (HCL), please visit the following Web site: