A Primer on Data Center Tiers

When you are exploring building your own data center or outsourcing your data center needs to a 3rd party provider, it is important to understand the quality of the data center based on tier level ranking.  What are data center tiers? Data centers are typically certified and rated via the TIA/942 standard and the rating methodology is used to rank data centers in terms of their levels of redundancy and other factors impacting uptime or expected infrastructure performance. In many cases, data center tiers are ranked from 1 to 4. The higher the number, the more expected uptime of the data center. Let’s take a look at the four main and currently accepted tier rankings:

Tier 1: Basic Data Center Infrastructures

Tier 1 is generally suited for small businesses. They feature 99.671% Uptime, no redundancy, and 28.8 hours of downtime annually. Tier 1 data centers are more than just staging servers in a large closet inside a spare office. What’s needed is a dedicated space for all necessary IT systems, i.e. a server room, a climate-controlled environment, a backup generator, and uninterruptable power supplies. The latter helps prevent spikes from damaging your mission critical equipment.

Tier 2: Data Center with Redundant Capacity Components

Tier 2 data centers feature partial redundancy in cooling and power, 99.749% uptime, and may experience about 22 hours of downtime per year. This tier incorporates all the characteristics of Tier 1. Although the cooling and power systems are not totally redundant, they still provide partial redundancy. Since tier 2 data centers exceed tier 1 requirements, they provide additional assurance that cooling and power components won’t shut down during important processes.

Tier 3: Concurrently Maintainable Data Centers

Tier 3 data centers are mostly utilized by larger organizations. This tier features 99.982% uptime and may only experience less than two hours of downtime per year. As tier 3 is N+1 fault tolerant, it provides at least 72 hours of power outage protection. Tier 3 data centers incorporate all the characteristics of tier 1 and 2. That’s why you will be able to shut down your data center for maintenance without affecting core IT processing.

When considering tier 3 data centers, you must implement redundant cooling systems and attach dual power supplies to different UPS units. This allows each UPS unit to be taken off-line without interrupting network connectivity and crashing servers. You should note that these types of data centers are not fault tolerant. They may need to share different components such as secondary cooling system components and utility company feeds that are stationed outside the data center.

Tier 4: Fault-Tolerant Data Centers

Tier 4 data centers usually boast 99.995% uptime annually, 96-hour power outage protection, and a 2N+1 fully redundant infrastructure. In many cases, annual downtime will not exceed 27 minutes. As you’ve guessed correctly, tier 4 data centers incorporate all the capabilities that exist in tier 1, 2, and 3 data centers. Since cooling and power components in tier 4 data centers are 2N fully redundant, they will need to be serviced by two different power distribution units (PDUs), UPS systems, generators, and utility power suppliers. With that, tier 4 ranked data centers often serve enterprise sized organizations.

The Importance of Data Center Tier Rankings

  • There may be times when you need to justify network availability to management in risk evaluation scenarios.
  • If you are hosting a critical application for a client, they may request to know what your data center ranking is, what certification standard is being used, and who certified your data center.
  • If you plan to move your data center to a cloud provider or external provider, tier rankings help you understand the risks involved in using external parties.

Agile’s inter-comnnected data centers feature multi-tenant space and have a solid infrastructure that can meet any data center colocation and disaster recovery needs. Agile offers up to 3+ data centers, which have all the features of tier 3 data centers as well as additional redundancy and other factors that bring it close to tier 4 data centers.  This strategy allows Agile to offer affordable colocation and disaster recovery services to organizations of all sizes to include large enterprise where they can rely on the highly reliable nature of Agile’s data centers with high service level agreements (SLAs) while not compromising quality of service.

Regarding our inter-connectivity, Agile believes that numerous tier 3+ data centers properly inter-connected offers greater resilience and reliability for stretched or diverse (load balanced) systems. The reason this practice is not used as much in the industry is that most data center providers don’t have a comprehensive, private and redundant network making carrier reliance and circuit costs critical factors in their single site vs. multisite deployment decisions. Agile’s approach of using multiple inter-connected tier 3+ facilities for higher reliability is enabled by our unique private network resources and services. In our model, not only does this provide higher reliability and resilience but we provide this more cost effectively than a single tier 4 deployment solution.

If you are looking to move your data into a highly available and inter-connected data center, you will never go wrong working with the Agile team.

If you would like to talk to our in-house experts, do not hesitate to get in touch with us through our Contact Us page.

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