Failover clustering

We have established that Network Load Balancing is a great solution for stateless applications, with a prime example being websites that you want to make highly available. What about other server roles or functions that you want to make redundant? Well, the opposite of stateless is stateful, so how about giving high availability to stateful pieces of technology? Failover clustering provides this level of capability, and can be used in cases where the nodes within the cluster are accessing shared data. This is a key factor to the way failover clustering is designed, the storage used by the cluster nodes must be shared and accessible by each node that needs it.

There are many different roles and services that can take advantage of failover clustering, but there are a solid four specific technologies that seem to make up the majority of clusters running in datacenters today—Hyper-V, file services, Exchange, and SQL. If you are working with any of these technologies, and...