The Truth About Data Center Tier Classifications

via @fibertown

The demand for proven high availability and redundancy in the data center is growing as more corporations are moving toward an outsourced model. Running mission critical applications and production systems from third party data centers allows IT leaders to reduce costs and sleep easy at night knowing their systems are protected and running 24/7/365.

Trusting your equipment and operations are in safe hands means believing that the site infrastructure and fault tolerance of the colocation provider is as solid as they say it is. Ask what classification their data center maintains and understand what the different classifications mean.

In 1995, Uptime Institute developed a Tier system for classifying data centers and outlining standards for site infrastructure requirements. A Tier 1-4 rating is given to data centers based on review of design topology and site sustainability.

Colocation providers and data center managers can loosely determine the classification of their site by examining the following standards:

Tier I – Non-redundant capacity components and single non-redundant path distribution paths serving the site’s computer equipment (basically a server room).

Tier II – Redundant capacity components and single non-redundant distribution paths serving the site’s computer equipment, guaranteeing 99.741% availability.

Tier III – Redundant capacity components and multiple distribution paths serving the site’s computer equipment. Generally, only one distribution path serves the computer equipment at any time. Tier III facilities are concurrently maintainable with all IT equipment being dual-powered and fully compatible with the topology of a site’s architecture.

Tier IV – Redundant capacity systems and multiple distribution paths simultaneously serving the site’s computer equipment. All cooling equipment is independently dual-powered, including chillers and Heating, Ventilating and Air Conditioning (HVAC) systems. Fault tolerant site infrastructure with electrical power storage and distribution facilities.

Classifications are officially determined by review of the data center by UT certified personnel

The Truth About Data Center Tier Classifications.