“Today we’re going to be talking in regards to the different data centre tier levels, what they cover and whether they’re still relevant.

The rackspace colocation tier levels were first started by the Telecoms Industry Association to define four levels of reliability within rackspace colocation, and exactly how well they are able to survive a fault such as for instance a mains failure or failure that is cooling.

A years that are few, the Uptime Institute brought out their version of the tier standards, which covered four levels of dependability, nevertheless they additionally offered a certification option, and even now there’s confusion between TIA and Uptime Institute standards.


We’ll focus on the Uptime Institute’s tiering because this is the the one that people use. The tiers run through anyone to four, with one being the least redundant and four being the most resilient.Tier One has little to no redundancy and when the energy goes, the whole site will go out. There’ll be no back-up power generation plus it’s only useful for applications and systems that you’re pleased to go offline at pretty much any point.

Tier Two, while it may still have a path that is single power and cooling, there will be back-up generation systems and some degree of redundancy built-in.

Tier three introduces the idea of concurrent maintainability. What this means is that you can lose any one component, or take one down for maintenance, while still providing service through to the data floor and the applications.

You might have a somewhat lower amount of redundancy while these elements are out but you’ll have resilience and failover in there. So you’ll typically have a couple of generators, additional air-con units (so you can take a unit off for maintenance), and some additional UPS. Tier Three is the most standard that is common the British which rackspace colocation align themselves to.

Tier Four may be the top tier within the Uptime Institute’s levels of tiering and, with that, you’re evaluating complete resilience through the entire entire site. So you’ll have two completely separate power paths, two completely separate cooling paths, two completely split system paths and, generally, a lot more than one feed off the mains grid, and this means you can lose any component inside the information centre and you’ll nevertheless have full resilience out to the rackspace colocation. Each of these power paths will have its resilience that is own in you are able to think of it like having two Tier Three rackspace colocation because you’ll have Tier Three standard on all of those paths.

You can find really few Tier Four standard data centres, just because the cost of adding in that additional level of resilience generally outweighs the benefits of doing things like good proactive maintenance and good testing of the systems. What you should really do is go and do your own due diligence. Therefore get look at the facility and satisfy the information centre team that is running it.

Learn what sort of planned maintenance that is preventative do, find out what testing they’ve place in place, and what sort of monitoring they’re doing.

If they’re doing things like full building black-out tests, where a mains failure is simulated, that’s great for ensuring the generators are run properly therefore the UPS’s are working effectively.

Having a well run Tier Three information centre will give you much generally better uptime than a poorly maintained and poorly run Tier Four rackspace colocation. Another good thing to look at is the overall level of resilience and uptime you will need in your systems and applications. Just having one’s body in a Tier Three or Tier Four data centre isn’t going to guarantee you a certain level of uptime and you should consider splitting your system, or your applications, across multiple Tier Three data centres – that way you can handle your failover along with your resilience in the applying layer and you also’re not reliant on the data centre itself.

Even a certified Tier Four data centre is only certified to 99.99% uptime, which still means you can have up to 29 minutes of unplanned downtime per year. So an application split across two Tier Three data centres will give a much higher aggregate uptime than having it hosted in a single Tier Four website.

I hope that was of good use and supplied a bit of background towards the tier criteria you have been aware of when considering information centers, as well as providing a bit of real-world context you should approach them as to how.

You can call us at 4D for more information about us and arrange a data centre tour.”