Top tips for greening your data center

Data center operators, and those that use them, are under increasing pressure to go green. Demand for data center capacity is being driven up by a number of factors that make driving efficiency through green principles a complex process.

But, the introduction of new emissions laws, such as the UK Carbon Reduction Commitment (CRC) Energy Efficiency Scheme makes the greening of the data center inevitable. The CRC has been causing great concern for data center professionals, who also need to save money on energy bills - as higher energy use may have tax levy implications, strengthen their green credentials to customers or reinforce a corporate social responsibility stance on climate change.

The European Union Emission Trading Scheme, and the US cap and trade carbon emissions schemes show that the greening of the data center is fast becoming a global concern.

In the meantime, demand for data center capacity remains locked into a continual growth curve, driven by a lack of consolidation of major users, such as Microsoft and Yahoo, the advent of services such as Software as a Service (SaaS) and cloud computing, and the lack of power availability to key strategic locations such as London's Docklands. These issues are in turn driving demand for ever more supply, heading towards a period where the gloomy predictions of analysts some years ago about data centers running out of power no longer look unrealistic.

This is particularly the case where technical advances such as smaller hardware footprints, blade servers and high-speed processing density coupled with a greater need for storage capacity are quite literally sucking the life out of the power grid. As power consumption increases, so does the need to dissipate the heat generated by processing, which increases air conditioning costs - which also require their own power supply to deliver benefits. It's easy to see how power, heat and cost are closely related and could easily spiral out of control.

Fortunately, data center practitioners can adopt a practical pathway to greening their data center or checking out the green credentials of their supplier, if they bear in mind several golden rules.

·         take a standard approach

A comprehensive set of standards and guidelines have been established to help data center practitioners design and implement a green strategy. Key standards and certified processes include ISO 14001, the Leadership in Energy and Environmental Design (LEED) or BRE Environmental Assessment Method (BREEAM) certification. Consortiums such as the Green Grid or organizations, such as ENERGY STAR, the joint program of the US Environmental Protection Agency and the Department of Energy, focus on making IT equipment more energy efficient.

The ISO 14000 series of standards aims to reduce the environmental footprint of a business and decrease the pollution and waste it can produce. As with all ISO standards, certification requires an audit from an accredited third party body. The US Green Building Council runs LEED and the Building Research Establishment runs BREEAM - both are programs that are designed to allow building designers, architects and constructors to follow best practice when it comes to materials and construction, leading to certification that describes the energy efficiency of buildings.

The Green Grid's approach has been to form a consortium of key industry players and stakeholders  - such as AMD, Microsoft, Sun and Google - and create metrics and standards that help understand and promote data center efficiency. Key metrics include power usage effectiveness (PUE), data center infrastructure efficiency (DCiE) and data center productivity (DCP).

·         conduct an audit

A comprehensive audit of existing data center facilities - or an examination of your current supplier - will reveal how big your environmental footprint really is. It will also point to areas where power can be saved and may even lead to the consolidation of one or more facilities or hosted space within a facility, offering cost savings and better green credentials.

The areas to focus on include how effectively server capacity and processing power is being used, whether redundant units are powered off or are constantly on standby, and if backups across corporate organizations are leading employees to inappropriately store data, or store it for longer than legally or usefully necessary.

Keep an eye on the future and take into account how capacity and processing power are expected to grow, when the peaks occur in usage, and when facilities can be powered down during lulls. Data center policies towards recycling (primarily waste and air recycling) and procurement are now being scrutinized as part of the audit equation.

·         optimize the floor, think about the air

Alternating hot and cold rack aisles is good practice when it comes to floor planning. This allows hot aisles to be somewhat temperature controlled by the cooler aisles, and limits the risk of hot air build up and equipment outages by reducing the amount that gets recirculated. Hot aisles can be isolated, making it easier to apply a specific cooling technique and therefore use cooling power more effectively. Water-cooled server cabinets, servers and CPUs are now available which offer more direct, effective cooling than air conditioning systems.

Another option is to utilize a system that channels air from outside the data center, known as fresh air cooling. Although this calls for servers that have a greater tolerance to a wide range of temperatures, it can be cost-effective. A complimentary approach is to allow servers to 'run hot' and therefore require less cooling, although they need to be configured to run that way and specialized equipment may be necessary. Technology that allows server racks to warm up the building is currently under discussion and might alleviate future heating bills.

·         power down

The conversion from AC grid power to the DC that drives data center equipment is inefficient, resulting in money being wasted on power bills, and excess heat generation within conversion units which are often mounted on or near racking. Power use can be reduced by 20% or more by switching to a DC supply and avoiding conversion.

Another step is to look at alternative sources of power. Gas microturbines or fuel cells are new technologies that more efficiently generate electric power and are becoming remarkably reliable. Also, sources of renewably generated electricity - such as wind or solar power - are available on the open market, and government rebates in some areas makes them a competitively priced option. It's may also be possible to generate your own power using the above methods and sell any excess back to the grid, offsetting existing power overheads.

·         manage the information lifecycle and virtualizes

Dust off your Information Lifecycle Management (ILM) policy and see how green it is. Chances are that it is optimized for greater security or cost savings, but not to be green. Although it's a generally accepted principle that data that has been saved most recently into storage or which needs accessing frequently, is stored on more expensive, faster media, the greening of your ILM policy could allow for much more.

For example, older, less-frequently accessed data could be moved to less expensive, slower storage media or indeed eliminated altogether - saving on energy costs to keep it alive long after it has passed its useful lifespan. Something as straightforward as enforcing email best practice with enterprise staff can eliminate the tendency to use inboxes as ad-hoc storage facilities for large multimedia data files, and reduce enterprise and hosted capacity usage.

Another technique which is gaining ground is server virtualization, where a single server can run multiple virtual servers in one box. Orange undertook a comprehensive virtualization and consolidation project in 2006 that enabled €11 million in savings in two years. During 2010, this level of total savings is forecast to double.

The subsequent reduction in power consumption equates to a reduced carbon footprint as well as reduced hardware capital and operating expenditure costs, and overhead from their associated power requirements. It's possible to calculate in advance the magnitude of expected cost saving and also the positive impact on the environment. However, enterprises and data center professionals must take the reins themselves for benefits to be realized.

Stewart Baines
Stewart Baines

I've been writing about technology for nearly 20 years, including editing industry magazines Connect and Communications International. In 2002 I co-founded Futurity Media with Anthony Plewes. My focus in Futurity Media is in emerging technologies, social media and future gazing. As a graduate of philosophy & science, I have studied futurology & foresight to the post-grad level.