A Shared Disk Quorum Has Been Detected

[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 http://go.microsoft.com/fwlink/?linkid=34707.] 

Topic Last Modified: 2008-08-26

The Microsoft Exchange Analyzer Tool queries the Active Directory directory service to determine the value of the msExchClusterStorageType attribute of the Mailbox server objects.

A value of 1 for the msExchClusterStorageType attribute indicates that the clustered mailbox server is hosted in a Cluster continuous replication (CCR) environment, and a value of 2 indicates that the clustered mailbox server is in a Single copy cluster (SCC). A value of <Not Set> indicates that the Mailbox server is a stand-alone server.

The Exchange Server Analyzer then queries the QuorumType property of the MSCluster_Cluster Microsoft Windows® Management Instrumentation (WMI) class to determine whether the quorum type set is Node Majority or not.

Finally, the Exchange Server Analyzer queries the MSCluster_Resource (WMI) class to determine whether the quorum resource has been defined as a shared disk quorum.

The quorum resource allows the cluster to maintain its state and configuration independently of individual node failures. The quorum resource stores a constantly-updated version of the cluster database and is accessible to all cluster nodes.

A shared disk quorum uses a quorum log file that is located on a disk hosted on a shared storage interconnect that is accessible by all members of the cluster.

If the Exchange Server Analyzer determines that all of the following conditions exist, the Exchange Server Analyzer displays a warning:

• The cluster type is Cluster continuous replication (CCR).
  
• The quorum type is not set to Node Majority.
  
• The quorum resource is a shared disk quorum.
  

The use of a shared disk quorum in a Cluster continuous replication (CCR) environment is not a recommended best practice.

• For Windows Server 2008, the recommended quorum is called a Node and File Share Majority quorum. For detailed steps about how to configure a failover cluster to use the Node and File Share Majority quorum model, see How to Configure the Node and File Share Majority Quorum.
  
• For Windows Server 2003, the recommended quorum is called a Majority Node Set (MNS) quorum with file share witness. This quorum model is available in Windows Server 2003 Service Pack 2 (SP2). It is also available in a hotfix for Windows Server 2003 SP1 described in Microsoft Knowledge Base article 921181, An update is available that adds a file share witness feature and a configurable cluster heartbeats feature to Windows Server 2003 Service Pack 1-based server clusters; however, Exchange 2007 SP1 requires Windows Server 2003 Service Pack 2.