Data centre 101

Summary:Secrecy seems to shroud the data centre arena -- all well and good for security's sake, but not so great when trying to pick a provider. RMIT IT Test Labs' Kire Terzievski pulls back the curtains to find what data centre options exist.


Contents
Introduction
Security
Building management
Cabling
Managed services
Second data centre
Data centre checklist
Sidebar: HP develops smart rack
About RMIT

Building management

All physical hardware devices come with environmental requirements that include acceptable temperature and humidity ranges. For that reason monitoring systems have to be in place.

HVAC (the heating, ventilation, and air conditioning system) controls the ambient environment temperature, humidity, air flow, and air filtering within a data centre. The data centre is required to connect this to the fire alarm and suppression systems, so the centre can properly shut down if a fire starts.

As fire needs oxygen, the HVAC system can feed the fire and can also spread deadly smoke into all areas of the centre, making the fire alarm even more important.

Raised floors
Servers and communications equipment squeezed into small spaces can create problems with cooling. Data centres have been designed with this in mind.

Today's servers dissipate so much heat that they produce hot spots, and can ultimately fail if not cooled properly. By cooling the entire floor to cool the servers you cannot remove the heat fast enough from all the racks, so data centres provide a raised floor.

Servers are placed in racks on raised floors with air conditioning units underneath to provide cold air directly to the front of the racks, enabling the servers to draw cold air from the front and blow it out the back. Also the rear of one rack always faces the rear of another -- this way the hot air is kept away from the front of the servers. Data centres are also monitored to keep them at a constant temperature.

Fire detection and suppression
Fire detection systems are quite sophisticated. These detection systems include things such as early warning systems that sample air molecules and detect potential fires up to two days before they happen, say in the event of overheating servers, which they will locate and detect.

Fire suppression systems are usually made up of FM-200s, which are similar to the Halon-based systems except that they don't damage the ozone. These systems are specifically designed not to cause damage to computer equipment.

Water sprinklers are simpler and less expensive than FM-200 systems. These can come in different forms. Wet pipes always contain water and are discharged by temperature control sensors. The disadvantage of this is if a nozzle or pipe breaks it can cause extensive water damage.

Dry pipes on the other hand don't hold any water. Water is held back by a valve until a certain temperature is reached. There is, however, a delay from when the water is released as it is not allowed into the pipes until the fire alarm has sounded.

UPS/Generator
Some data centres are located on top of multiple power grids driven by power companies. Power can also come from UPS battery backup units and diesel generators. Generators typically have a sufficient amount of fuel to provide power in an event of a long power disruption.

Connectivity
Typically, a data centre will have multiple Tier 1 connections (100M) entering the building. This enables them to offer multiple levels of redundancy for your Internet connection. Some are connected to some of the world's largest internet backbone service providers and strategically connected to major hubs to improve data speeds to the USA or other parts of the world.

By having direct links into the Telstra, Optus and Vodafone networks, you not only have redundancy like we mentioned before but also the expertise and the high quality of service that large telcos can have in wide area networks.

Topics: Security, Big Data, Hewlett-Packard, Networking

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