Ensuring High Availability and Business Continuity

Virtualization and VMware vSphere in particular enable advanced ways to provide high availability and business continuity. This chapter helps the administrators to understand Windows clustering and the different types of clusters, use vSphere's built‐in high‐availability functionality, recognize differences between high‐availability solutions, and understand additional components of business continuity. Even in non‐virtualized environments, there are multiple ways to achieve high availability for Operating System (OS) instances and applications. The Network Load Balancing (NLB) configuration involves an aggregation of stateless servers that balances the requests for applications or services. Unlike NLB clusters, Windows Server Failover Clustering (WSFC) clusters are used solely for the sake of availability. Business continuity is about ensuring that the business can continue operating in the face of a significant event. High availability deals with business continuity from a fairly narrow perspective.