Making Your Exchange 2003 Organization Fault Tolerant

To design a reliable, highly available messaging system, you must maximize the fault tolerance of your messaging system. Fault tolerance refers to a system's ability to continue functioning when part of the system fails. An organization that has successfully implemented fault tolerance in their messaging system design can minimize the possibility of a failure, as well as the impact of a failure should one occur.

To make your Microsoft® Exchange Server 2003 messaging system fault tolerant, you must implement hardware and software that meets the requirements of your service level agreements (SLAs). Although many fault tolerant server and network components can be expensive, the features of Microsoft Windows Server™ 2003 and Exchange Server 2003 can help you maximize fault tolerance, regardless of your hardware and software budget.

A common misconception is that, to achieve the highest level of availability, you must implement server clustering. In actuality, a highly available messaging system depends on many factors, one of the more important being fault tolerance. Server clustering is only one method by which you can add fault tolerance to your messaging system. To achieve the highest level of availability, you should implement fault tolerant measures in conjunction with other availability methods, such as training information technology (IT) administrators on your availability processes.