Energy-smart data centres

Going green can be the secret to significant cost savings as well as aggressive performance growth. Implementing a comprehensive strategy that includes virtualisation and consolidation as well as best practices for power and cooling optimisation can help businesses achieve immediate benefits.

Companies go green for a variety of reasons. Thanks to ongoing increases in global electricity prices since 2002, green initiatives are often conceived as a response to the rising cost of energy. Some businesses go green simply to improve customer and public perception of their organisation. Still others are driven by environmental concerns to minimise the impact of global carbon dioxide emissions.

Whatever the motivation, IT is a key component of green initiatives. IT infrastructure accounts for a disproportionate share of energy relative to head count and operating costs - and these energy issues can inhibit business innovation and growth.

 

Power and cooling capabilities are maxed out in many data centres, and power and cooling expenses frequently outstrip the cost of IT equipment. IT managers are also grappling with operational issues such as difficult-to-manage ‘hot spots' while trying to meet the needs of an ever-increasing server population.

Conflicts between IT and facilities management groups are often the cause of inefficient practices in the data centre. These conflicts typically surface when organisations are planning for upcoming data centre changes such as consolidations and expansions, new re-dundancy requirements, or incremental power requirements.

IT managers are typically concerned with the ability of the IT facility - including its space, power, and cooling capacity - to fully support server consolidation, virtualisation, or high-performance computing initiatives, and the ability of existing server room and data centre cooling systems to support new equipment. For example, in one typical enterprise usage scenario, power distribution and cooling equipment consumed 59 percent of data centre power, whereas compute servers accounted for less than 30 percent.

Existing server room and data centre power distribution systems cannot always support future growth - and organisations frequently cannot afford the costs associated with a major business disruption. Meanwhile, facilities management groups have different priorities when planning data centre changes.

They must consider power usage caps from the utility company as well as energy costs, which often exceed equipment costs. And in many cases, companies are literally running out of space in the data centre because existing server racks are full. Moreover, the data centre may be running out of circuit breakers. Facilities managers often cannot deploy any additional servers until a new data centre is brought online.

Simplification

Because energy consumption is about much more than just the IT equipment, organisations should take a comprehensive approach to greening the data centre. They can start by using energy-efficient platforms with built-in power management features. For example, energy-efficient servers should include high-efficiency power supplies and optimised thermal design, and can also include silicon changes, component changes, and energy-efficient motherboard design.

Organisations can also optimise the office IT environment through effective client power management. In addition, data centre optimisation measures such as enhancing system utilisation through virtualisation and workload management technologies, highly efficient cooling architectures, and energy-efficient storage design can complement these efforts and enhance efficiency.

A positive change in the energy usage of IT equipment can have a direct effect on power and cooling requirements. For example, in one data centre usage scenario, a 10 percent improvement at the server level netted about an 8 percent improvement at the facility level.

However, efficiency improvements in cooling or power delivery were relatively independent; a 10 percent increase in power delivery efficiency manifested itself as about a 4 percent improvement at the facility level.

Pinpointing facility and IT improvements that enable efficient operation can offer significant opportunities. For example, simply running the facility at a slightly higher temperature than usual can often provide an opportunity to increase efficiencies. Coupled with air-handler energy-efficiency options, savings of 5 percent or more at the facility level are not uncommon.

Savings may result from staged compressor operation, slowdown of airflow with variable-frequency drives, increased chiller efficiency, or minimised condensation and re-humidification in the air handler.

Advancing efficiency

Through virtualisation and consolidation, enterprises can reduce the number of physical servers in the data centre while dramatically increasing compute capacity.