Holistic approach maximises energy efficiency

The carbon-neutral datacentre is still a long way off, but enterprises can make their datacentres more energy efficient by matching supply to demand.

The carbon-neutral datacentre is still a long way off, but enterprises can make their datacentres more energy efficient by matching supply to demand.

Whether the scientific environmental lobby gets your vote or not, the 'greening' of enterprise IT cannot be avoided. Gartner research vice-president, Rakesh Kumar, tells Computer Weekly, "The bottom line is that we're seeing an exponential rise in the cost of running datacentres."

He says IT managers have been "getting away with murder" because it is often the facilities department that picks up the electricity bill. "Power hasn't been an issue for IT organisations in the past because it hasn't had to be," Kumar adds. But now the analyst firm is advising companies that what accounted for 10% of the annual IT spend could soon rise to 25% by 2010.

So, the idea of trying to build a green, carbon-neutral datacentre therefore may not seem so far-fetched. But, says Kumar, it is a long way off. "I don't see the concept of a carbon-neutral datacentre as tenable in comparison with the way that retailers, say, can use the impact of their policies on plastic bags to offset emissions." This cannot happen until IT can effectively measure the 'consumption' of every application, server or other datacentre component and compare that with the amount of business benefit or profit they deliver.

"But I do think the idea of making it more carbon efficient or 'green' is much more feasible," he says, adding that datacentre IT suppliers are already developing technological advances that can enable lower power consumption rates in the datacentre through more efficient equipment use, cooling and the use of renewable energy sources and heat exchanges.

"The datacentre must be able to adapt itself to the energy workload it is running and behave like a living, breathing organism by being able to react to changes in demand," Kumar says. This is best achieved in the initial design stage, where provisioning can be matched to current demand. Datacentre location can play a big role here, perhaps enabling access to lower cost or renewable energy sources. By contrast, the current trend towards locating datacentres close to big cities just so they are near to the IT department is "inexcusable" with today's remote management capabilities, he adds.

Specifying modular datacentre infrastructure components will allow the datacentre to grow with the needs of the business, as opposed to buying and running spare computing capacity and components upfront. And specifying a complete monitoring environment, with the necessary sensors and management tools, will enable the IT organisation to ensure it has 'right-sized' its datacentre to meet IT service level demand.

Chandrakant Patel, sustainable IT ecosystem software lab director and enterprise systems fellow for HP Labs, agrees that the first step to a more energy-efficient datacentre is better matching supply to demand. "You wouldn't buy a ceiling fan for a house with no knob, would you?" he asks, adding that many organisations are still not taking a holistic approach, from design through to operations, to management and control in this important area of their IT infrastructure. "I think a carbon-neutral datacentre will only become a possibility when you can right-provision the design and day-to-day use of the datacentre," he adds.

Patel says he has a number of Hewlett-Packard datacentres in India under his control from his desk in the US. "On the whole, datacentre provisioning is still very rule of thumb," he says. But the HP datacentres under his remit have been modelled using computational fluid dynamics to track the thermal changes that can affect the smooth running of high-density racks of blade servers, for example. And thousands of sensors allow heating, ventilation and air conditioning (HVAC) requirements to be tracked and adjusted according to model parameters. Last year HP introduced thermal zone mapping to its datacentre offerings, he adds.

"If you don't employ such tools, it is naturally easy to over-provision," says Patel. "You will run your servers conservatively in terms of load and the inlet [HVAC] temperature at the racks can be very low, which can all waste a lot of power." Like BT and other organisations for which the datacentre is their very bread and butter, Patel explains that HP has discovered the heat and load tolerances of servers and their peripherals can be far greater than those specified by the manufacturers. "We run our centres at about 25°C," he says, "where the norm is about 19°C. We modulate our fans so they run at the right speed to regulate the temperature and use as little power as possible. I would say not having done the thermodynamic work is one of the main reasons for having an over-provisioned datacentre."

According to Gartner, more efficient uninterruptible power supply (UPS) for back-up in the event of outages can carry far more weight in terms of effectively valuing datacentre efficiency than the traditional means of looking at datacentre costs per square foot of floor space. "There have been huge advances in UPS equipment, like those using cell-based generators," explains Kumar, "where, although they can be as much as 20% more expensive than traditional generator-based systems upfront, they can be 60% and up to 80% or 90% more power efficient, paying for the extra cost over their lifecycle."

In fact, Gartner states that, on average, server farms consume only 30% of the total energy used in the datacentre. The remainder is lost in heat, noise and other, facilities-related energy areas. "I would focus on that 70% facilities stuff," advises Kumar, "and maybe swap out or consolidate the most inefficient servers." Nevertheless, it is here that the green spotlight has fallen most recently, with server virtualisation being touted as a green technology.

A recent Datamonitor survey found that one in three companies use software, network or storage virtualisation already as part of a green IT strategy. Vamshi Mokshagundam, Datamonitor technology analyst, says these companies were attracted by the dual benefits of rationalising their IT estate costs and cutting energy overheads. Within this trend then, it also found more than two-thirds of enterprises had a formal programme in place to recycle their IT assets. And the emergence of more power-efficient technologies such as light emitting diodes (LED) and solid state disks (SSD), as well as software as a service (SaaS) for its shared delivery infrastructure can be seen in a wider context than one that is only applicable to building a carbon-neutral datacentre.

And despite the fact that chip makers Intel and AMD are developing more energy-efficient processors for virtualised environments, Gartner's Kumar says suppliers are still building their understanding of the relationship between energy management and virtual software management in particular. By contrast, it may be more productive to look for 5%-10% savings on datacentre costs through renewable energy use, he suggests.

Here the idea of 'free cooling' or using outside air to regulate datacentre temperatures is not new, but holds much more promise, according to Zahl Limbuwala, technical operations director at internet media firm Real Networks and head of the datacentre specialist group of the British Computing Society (BCS). Equally, solar and wind energy are sensible options because they rely on abundantly available resources, depending on geographic location. But Limbuwala is most sceptical about biodiesels. "Most datacentres have generators as back-up power sources and it has been suggested biodiesel could be a more green alternative to diesel," he says. "But there is a belief that it may not be stable enough to store for long periods, where the worst case scenario would be that it blocks the fuel pumps when used in a power cut - the very point at which you need the generators to work."

Limbuwala does, however, agree with the rest of our experts that effective measurement and monitoring is the first and best step towards developing parameters, practices and technologies that can make the carbon-neutral datacentre a reality. "The BCS is working to create a comprehensive model of datacentre environments that you don't have to be a mathematician to understand, so IT organisations can begin to better understand and address datacentre power consumption requirements."

Bank implements technology to cut energy costs

Barclays recently revealed it has entered into a partnership with Hewlett-Packard to introduce energy-efficient technologies in the bank's major new datacentre in Gloucester.

HP Dynamic Smart Cooling technology will feature as part of a package of energy-saving measures that Barclays says will allow it to save up to 13.4% on its total datacentre energy usage or the equivalent of approximately 7,470 metric tons of CO2 a year.

Elaine Heyworth, head of environmental management for Barclays Global Retail and Commercial Banking, says it has been working with HP for several years on basic hardware and software requirements, but wants to extend this to the datacentre. "We also considered drivers that we might see in the future around customer demand and legislative control," she says.

The HP system uses a network of sensors to adjust the air handlers and modulate cooling energy based on demand from the servers and storage devices. Heyworth explains, "Dynamic Smart Cooling allows us to pinpoint exactly which server needs to be cooled and therefore allows us to considerably lower our energy emissions for the datacentre. Power and cooling are currently taking up the greater part of our datacentre utility expenditure and Dynamic Smart Cooling provides us with the ability to reduce these costs."

Prior work includes power-optimised servers, the adoption of HP BladeSystem and HP Thermal Logic technology and virtualisation-based consolidation. According to Barclays, these initiatives have already achieved energy savings ranging from 18% per server to 40% per datacentre around the globe.

Barclays' environmental improvement targets, set in 2005, include reducing its CO2 emissions by 20% by 2010.


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