Cost, speed, and reliability tradeoffs between N+1 UPS Configurations
There is an increasing trend towards N+1 UPS architectures – rather than 2N – as IT fault tolerance through software continues to improve. Data centres implement varying degrees of redundancy, based on the criticality of the load(s) they support. Dual path architectures (two separate power paths, for example) provide the highest levels of availability, as maintenance or failure can occur with any system without taking down the load.
In today’s data centres, however, we are seeing more and more fault tolerance occur through software, at the IT layer. With technologies such as virtualization and hyper-convergence, no longer is it true that a server going down means the IT mission goes down. If a physical server goes down due to an upstream failure or is scheduled to go down for maintenance, the data centre can migrate the business function(s) over to another server, another pod, another room, or a separate data centre.
While availability is still the critical objective of data centres, some are finding that this can now be achieved with N+1 redundancy of key physical infrastructure systems like the UPS. The two common ways N+1 can be achieved are paralleling multiple unitary UPSs together or deploying a single UPS frame with multiple internal modules configured for N+1 redundancy. N+1 has become a more common UPS architecture for data centres, and so it becomes more important to understand the trade-offs of different approaches.
This enables data centre decision makers can make the most educated decision possible given their risk tolerance, budget, and timeline. Schneider Electric has released a white paper that clarifies the different methods of achieving N+1 redundancy of your UPS system(s). It also quantifies the capital cost, deployment time, efficiency, and reliability tradeoffs, and discusses the importance of fault tolerance within the UPS to ensure reliability, availability, and maintainability needs are met.
This article was published in partnership with Schneider Electric.