A cluster is a set of independent computers that work together to increase the availability of services and applications. The clustered servers (called nodes) are connected by physical cables and by software. If one of the nodes fails, another node begins to provide service through a process known as failover.

You can use the Microsoft® Management Console (MMC) snap-in, Failover Cluster Manager, to validate failover cluster configurations, create and manage failover clusters, and migrate certain settings to a cluster running the Windows Server® 2008 R2 operating system. You can also configure and manage failover clusters by using Windows PowerShell. These Help topics describe methods for using Failover Cluster Manager. For more information about using Windows PowerShell for failover clusters, see http://go.microsoft.com/fwlink/?LinkId=135119 and http://go.microsoft.com/fwlink/?LinkId=135120.

In Windows Server 2008 and Windows Server 2008 R2, the improvements to failover clusters (formerly known as server clusters in Windows Server 2003) are aimed at simplifying clusters, making them more secure, and enhancing cluster stability. Cluster setup and management are easier. Security and networking in clusters have been improved, as has the way a failover cluster communicates with storage.

Note that the Failover Clustering feature is included in server products such as Windows Server 2008 R2 Enterprise and Windows Server 2008 R2 Datacenter. The Failover Clustering feature is not included in Windows Server 2008 R2 Standard or Windows Web Server 2008 R2.

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