Endurance 4000/sup TM/-enabling fault tolerance for Windows NT servers

The growing dependency of Industry and Commerce on computer systems has created a need for technologies capable of ensuring uninterrupted business activity. Many companies now demand continuous availability of systems for their 7/spl times/24 hour business operations. The low cost and high performance of Intel based systems and the emergence of today's operating systems such as Windows NT/sup TM/, makes these systems increasingly attractive to large numbers of companies as they find new applications in the Client/Server and Internet/Intranet environments. The issues the manager faces in deploying technology to enable 7/spl times/24 availability of business systems can affect every aspect of the operation. The initial hardware and software cost can be the lowest cost item since most high availability technologies require specially modified applications software to take advantage of all the availability features of the system. There are several systems which claim to offer "fault tolerance" but in fact lack features which are associated with traditional minicomputer and mainframe fault tolerant systems which are deployed in mission critical applications such as funds transfer, order processing, banking and process control. This paper will discuss a unique approach for enabling fault tolerance on low cost Intel based systems running the Windows NT/sup TM/ operating system without requiring special modifications for off-the-shelf or bespoke applications.