Different Tiers in a Data Center

 

The days of having a ‘computerroom’ in your own company are fading. Nowadays most enterprises outsource their technical environment off-site to a professional datacenter. ICT at this point is business critical for almost any company and environments should be high available, secure and have a disaster recovery plan. Having said that, it’s important to know there is a quality difference among datacenters, qualified as Datacenter Tiers.

 

Several key components play a part in the quality of a datacenter such as :

 

• Electrical power redundancy
• Fire protection
• Physical security parameters
• Cooling redundancy
• Environmental control
• Carrier neutrality
• Carrier entry points

 

In 2005 it published ANSI/TIA-942, Telecommunications Infrastructure Standard for Data Centers, which defined four levels (called tiers) of data centers in a thorough, quantifiable manner.

 

Tier 1 = Non-redundant capacity components (single uplink and servers).
Tier 2 = Tier 1 + Redundant capacity components.
Tier 3 = Tier 1 + Tier 2 + Dual-powered equipments and multiple uplinks.
Tier 4 = Tier 1 + Tier 2 + Tier 3 + all components are fully fault-tolerant including uplinks, storage, chillers, HVAC systems, servers etc. Everything is dual-powered

 

Tier 1: Guaranteeing 99.671% availability.
Tier 2: Guaranteeing 99.741% availability.
Tier 3: Guaranteeing 99.982% availability.
Tier 4: Guaranteeing 99.995% availability.

 

It’s key to evaluate every possible failure scenario when choosing a datacenter partner and checking availibility. At minimum you should ask yourself :

 

• What about physical security, who is allowed in the datacenter ?
• Are people required to sign in ? Present their ID ?
• How is backup electricity managed ? By diesel engines ? Is this procedure tested on a regular basis ?
• Do they present redundant circuits in a rack ?
• How is carrier feeding managed ? Is there an intro at different locations of the datacenter building ? Are these carriers following the same path or redundant ?
• Which carriers are available in the datacenter ?
• How is cooling managed ? Cold-Warm corridor ? is it monitorred by the datacenter ?
• Is there an airport nearby ? (yes, this is about disasters! there are regulations about this)
• Is there a raised floor ? Is there moisure detection ?
• What about the roof ? Dual layered ? Moisure detection ?
• How is fire surpression managed ? By gas or water ?
• Is there overhead cabling ?

Security is a big topic, as network security has been improved over the years. When attacks come from the inside (eg : from a person on the console of your environment in the datacenter) network security is easily bypassed. It’s important your datacenter partner works in full confidentiality and has a strong physical security and security logging concerning who’s entering the datacenter at which time. It’s obvious only you should have access to your hosted racks by key, keycard or biometry.

 

Another important factor when choosing a datacenter partner is about communication. As it seems less important, this is one of those factors which can easily blow up a customer relationship. First of all there should be a communication channel concerning mayor outages or planned interventions inside the datacenter. Secondly you should be able to contact your datacenter partner 24/7 when your racks are down. While this seems obvious, it’s important to check and evaluate how the datacenter partner is handling these events. Related is the Service Level Agreement, which should be investigated carefully. If you provide services to your own customers, you should be able to allign your SLA’s to these of the datacenter (back2back).

 

Among all other technical questions, use your common sense. Have a chat with your account manager or the datacenter owner and put a list of questions together. Chat about outages, escalation procedures and innovation or datacenter growth. Ask for public references and give them a call!

Hope this helps when choosing your datacenter partner and clarifies datacenter tiers. Happy hunting!