Windows Server 2008 Failover Clustering

A failover cluster is a group of similar computers (referred to as nodes) working in a coordinated fashion to increase the availability of specific services or applications. You typically employ failover clusters to increase availability by protecting against the loss of a single physical server from an unanticipated hardware failure or by proactively maintaining a single physical system. Clustering protects against planned downtime as well as unplanned because the proactive maintenance of hardware usually takes down the system and results in system unavailability.

If you’ve worked with a failover cluster via Microsoft Cluster Service (MSCS) using Windows NT Server, Windows 2000 Server, or Windows Server 2003, you already understand the basics of failover clustering in Windows Server 2008. Like those earlier Windows Server clustering technologies, failover clustering in Windows Server 2008 uses shared disks in a shared-nothing model to provide multiple servers one-at-a-time volume access.