Such nostalgia is invariably short-lived, though. Today, it's all about immediacy of access to information, applications and one another. Even small enterprises are increasingly online, mobile and Web 2.0-driven, to the point where IT is no longer just a business tool. It is business -- the heart and the circulatory system through which most transactions flow. If your IT systems fail, your daily operations follow -- and if the outage lasts too long, your business may fail.

So small-to-midsize businesses should ask themselves how they can create a high-availability infrastructure that responds robustly to new-age business challenges and disruptions. Server clustering and data mirroring can play an important role in implementing high availability. They can also serve as a cornerstone to an effective business continuity and disaster-recovery strategy, and -- good news -- they can be very affordable.

Clustering and mirroring for high availability

Server clustering is the answer for several objectives: creating scalability, load balancing and, of course, increasing system availability. Clustering for high availability allows the automated failover between servers in the cluster, providing close monitoring of applications and all their components, including operating system, server hardware, networking and storage.

The clustering software determines when to perform a failover by continually checking each application's "heartbeat" signal, and if one system has a problem, the application on another server in the cluster takes over. To the outside world, the cluster appears to be a single system, but intelligent redundancy within it creates high availability.