A high availability solution maintains continued functioning of applications in the event of computer failure, where data and applications are available using redundant software and hardware. High availability can refer to any software or hardware that provides fault tolerance, but generally it has become associated with clustering.
A cluster is a group of independent computers working together as a single system to ensure that mission-critical applications and resources are highly available. The cluster is managed as a single system, shares a common namespace, and is specifically designed to tolerate component failures and to support the addition or removal of components in a way that is transparent to users.
Clustered systems have several advantages, including fault tolerance, high availability, scalability, simplified management, and support for rolling upgrades.
In a high availability cluster with Storage Foundation for Windows, you configure dynamic cluster disk groups and volumes for the application on shared storage and install the application database and log to the appropriate SFW volumes.
The following figure shows an example of a two-node high-availability configuration.