Failover Cluster Design Guide

Applies To: Windows Server 2008

A failover cluster is a group of independent servers that are running Windows Server® 2008 and working together to increase the availability of services and applications. When a failure occurs on one computer in a cluster, resources are redirected and the workload is redistributed to another computer in the cluster. You can use failover clusters to ensure that users have nearly constant access to important server-based resources.

In Windows Server 2008, the changes to failover clusters (formerly known as server clusters) are aimed at simplifying cluster setup and management, making the clusters more secure and stable, improving networking in clusters, and improving how failover clusters communicate with storage. The interface for failover clustering, called the Failover Cluster Management snap-in, simplifies the process of validating failover cluster configurations, creating and managing failover clusters, and migrating some resource group settings from a cluster that is running Microsoft Windows Server® 2003 to a cluster that is running Windows Server 2008.

For more information about how failover clusters work and how to set up a failover cluster in a test lab, see Failover Cluster Step-by-Step Guide: Configuring a Two-Node File Server Failover Cluster (

About this guide

The purpose of this guide is to help you, the IT professional, create a design for a failover cluster that meets the requirements of your organization. This guide highlights your main decision points as you plan your failover cluster deployment. Before you read this guide, you should have a good understanding of the priorities for availability in your organization and the hardware available for your failover cluster. For more information about defining priorities for availability, see Appendix B: Identifying Availability Requirements for a Failover Cluster and Identifying Your Failover Cluster Deployment Goals.

This guide describes a set of deployment goals that are based on which type of server roles (for example, a file server) or applications you want your cluster to support, and on whether the design of the cluster includes additional servers to allow for disaster recovery. You can focus on one or a combination of these deployment goals, which include:

  • High availability for a file or print server

  • High availability for a service (such as Dynamic Host Configuration Protocol (DHCP)) or application

  • High availability for a server running the Hyper-V virtualization feature

  • Increased availability for multiple existing servers in your organization, for example, several file servers and a print server, achieved with minimal cost for additional server hardware

  • High availability for multiple services and applications (that can all run on one failover cluster)

  • High availability and a disaster recovery option for file, print, or applications

After you gather your organization's requirements and create a design that maps to your requirements, you will have the information necessary to follow the corresponding procedures in the Failover Cluster Deployment Guide (

In this guide