One solution for a highly available Exchange 2003 server is to cluster Exchange using the Windows Cluster Service found in Windows 2000 Advanced Server and Datacenter Server, as well as Windows Server 2003 Enterprise Edition and Datacenter Edition. Clustering is not new to Exchange 2003; however, Microsoft has significantly improved the way clustering is implemented in Exchange 2003. These changes affect permissions, setup behavior, and dependencies. Support for the Windows Cluster Service is in Exchange Server 2003 Enterprise Edition only; it is not a feature in Exchange Server 2003 Standard Edition.
In order to understand these changes, an understanding of Windows clusters is helpful and necessary. Therefore, ...