A Shared Disk Quorum Has Been Detected

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 t o 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.