Failover Clustering is a high-availability feature, which requires the certified hardware (referred to as Hardware Compatibility List or HCL) or Window Server catalog for the Windows Server 2003 or earlier operating systems. To prepare and install the Windows operating system cluster, from Windows Server 2008 onwards, it is no longer a requirement to follow an HCL test process as it is replaced by a new process called Cluster validation. SQL Server 2008 R2 Failover Clustering is built on top of the Windows operating system failover clustering to provide availability for the entire SQL Server instance. The downtime for an application is minimized and 99.99 percent uptime is guaranteed. The Failover Clustering functionality represents an SQL Server instance with a Virtual SQL network name or Virtual SQL IP address and performs failover from one node to another, which is handled by Windows Server cluster service. Failover Clustering is only a feature...