Chapter 5. Failover clustering

Although redundant component design, such as dual-power supplies, provides fault tolerance at a component level, failover clustering operates at the server level, enabling ongoing operations in the event of a complete server failure. Complementary to component redundancy, failover clustering is a commonly used high availability technique for SQL Server implementations and is the focus of this chapter.

In addition to the requisite SQL Server skills, successfully designing and administering a clustered SQL Server environment requires skills in a number of areas, including the configuration of cluster-compatible hardware components. While Windows Server 2008 has made clustering SQL Server somewhat easier, it's still a complex process requiring considerable planning and broad skills.

Rather than attempt to provide full coverage of the clustering design, creation, and administration process (such a goal would require at least an entire book!), this chapter focuses on installing a clustered SQL Server instance. Let's begin with a broad overview of clustering, exploring its benefits and limitations from a SQL Server perspective, and tackling important preinstallation configuration tasks.