2N vs. N+1: Data Centre Redundancy Explained

by Tom Gorman, Director of Operations - Ireland


The only certainty is uncertainty. From powerful storms to unexpected power outages, you never know what life is going to throw your way, or your data centre’s way. That’s why a plan for redundant systems is your data centre environment’s best friend when the unexpected happens.


What is data centre redundancy?

Redundancy refers to a system design where a component is duplicated so that in the event of a component failure, IT equipment is not impacted. For example, having redundant power in case there's a power outage. The main goal of redundancy is to ensure zero downtime, even in worst case scenarios.


Why is data centre redundancy important?

The maximum tolerable period of disruption (MTPD) is continuing to decrease for most companies because there is less tolerance for their operations experiencing any sort of downtime. There is growing pressure and necessity for companies to be able to maintain uptime and recover more quickly from a disruption, no matter how it was caused.

There are many components in ensuring data is safe and secure. Having a well planned redundancy design implemented into your data centre environment is one of those crucial components. System failures can have serious and direct impact on an organisation's bottom line, business operations, and customer experience, resulting in devastating revenue loss, missed business opportunities and a tarnished reputation. According to an annual survey conducted by the Information Technology Industry Council (ITIC), 98% of organisations say that a single hour of downtime costs over $100,000. Beyond dollar signs, downtime can severely impact the productivity of your workforce when they're tied up with frantically trying restore systems and data instead of focusing on other core focus areas for your business.


What's the difference between 2N vs. N+1?

So what is the difference between 2N vs. N+1? It may seem like an algebra equation at first and, well, it basically is a very simple equation. But first, you must understand what N means. Let's break it down.