Cred - or croak?

The practicalities of going green in the data centre are proving to be more difficult than first envisaged.

Over the last two years the 'greening' of data centres has been a descant to the corporate utterances from most of the operators and equipment vendors selling into that industry.

Many data centres took the green pledge not only because they affirmed its principles and didn't want to damned by default, but also as they realised that IT in general was receiving more than its fair share of criticism. Not only were data centres using vast amounts of energy to run servers, power control units, cooling and air-conditioning units, but the resultant heat generated was not reused constructively.

The attention this brought raised the spectre of regulation, and the data centre sector rapidly realised that it needed to be seen to be acting to address environmental issues to offset any possibility of legislative controls from outside agencies.

Throughout 2007, and the first half of this year, 'getting greener' was the defining mantra of the data centre sector, and the unifying theme of every data centre industry event. Presentations were replete with frameworks and guidelines designed to promote best practice in running data centres on more environmentally sound principles.

However, as operators and analysts alike attempted to implement them, some, well, inconvenient truths started to emerge. The realpolitiks of green IT, as it were, have shown that the green IT ideal is not as achievable as the market was being told two years ago, and that basic tenets of green IT are much less feasible in practice than in theory.

"It is true that IT equipment is becoming more and more efficient; it is equally true that processing power is becoming greater and that this requires even more power," rues Alex Rabbetts, managing director of data centre consultancy Migration Solutions.

"You can't say we, as an industry, are 'green' when there are plans to build more data centres, and deploy more technologies to meet demand. Any power efficiencies realised to date have been used as an opportunity to add new features."

Power consumption is perhaps the foremost example of this. There is no doubt that data centres consume significant amounts of electricity. A study last year by chip maker AMD found that in 2005, US data centres and their associated infrastructure alone consumed five million kilowatts of energy, the equivalent of five 1,000MW power plants.

Total data centre electricity consumption in the US, including servers, cooling, and auxiliary equipment, was approximately 45 billion kWh, resulting in total utility bills amounting to $2.7bn. Total data centre power and electricity consumption for the world AMD estimated to cost $7.2bn annually. The report also estimated that data centres' electricity demands had doubled since 2000.

Data centre power efficiency

Chip makers and server vendors have aimed at reducing the consumption of their products; blade servers and virtualisation should use less electricity than old-style densely-populated server 'farms'. But, in general terms, any savings would be predicated on current demand remaining flat until the extant installed base is fully replaced by more energy-efficient upgrades. However, data centre demand is not flat, it is growing and as many new blade servers as replacements are being installed. Google won't tell, but some sources estimate that the search giant runs over 450,000 servers, with new clusters regularly being added around the world.

"Finding efficiencies in power consumption is not necessarily going to result in greener data centres today, but [it] will at least go some way to ensuring that future data centres are managed as well as they can be," believes Simon Perry, principal associate analyst - sustainability, at market-watcher Quocirca.

"There is a very clear case for ensuring that today's data centre is running at the highest feasible efficiency level, especially as energy prices are at high levels. What I don't think is clear is that we can look at the server density trends of the past decade as necessarily pointing to the future path of data centre requirements."

Perry sees companies with many disparate data centres consolidate them (often by a factor of ten), and thus the energy density requirements for the remaining (larger) data centres become higher than they were before - "but that change is a one-off rather than then setting a path for the future," Perry adds. At the same time, he is not convinced that exponential growth seen over the last six years will continue: "The previous decade's growth has come from the businesses getting the Internet, and all its commercial possibilities."

The question is, in relation to the average business's data centre requirements, whether there is enough left to do in that wave to continue the trajectory of previous decade's growth into the next decade. "One answer I've been given is that 'IT has [no problem with] finding something to do with the spare capacity'. This 'build it and they will come' approach is mindless in the context of efforts to reduce energy usage, reduce costs, and basic good business governance."

Migration Solutions' Alex Rabbetts agrees: "Some data centres are now claiming to be 'green'; this is simply not true. There can never be such a thing as a 'green' data centre. Data centres necessarily consume huge amounts of power and produce huge amounts of heat that is largely released to the atmosphere."

Reuse of heat, reductions in power, consideration of other aspects such as materials used, packaging and recycling can all contribute to reducing the carbon footprint of a data centre, Rabbetts adds, but it will never create a 'green' data centre.

Data centres are sweating because Internet traffic is intensifying. To standard enterprise business applications, and specialist applications being migrated to the Web, add the onset of Cloud computing and 'Software as a Service' usage. Add to the mix digitalised voice signals, and traffic generated by IP-manageable devices such as security alarms. And, of course, the Internet is increasingly being used as a primary delivery medium for all manner of value-added online recreation, such as streamed video, gaming, and gambling. Their popularity, enabled by the broadband boom, means that data centres will not be cooling down through lack of utilisation any time soon.

AMD's environmental report

The month following the publication of the AMD finding, the US Environmental Protection Agency estimated that suggested that US data centres consumed about 60 billion kWh, which equated to around 1.5 per cent of total US consumption; its 'Report to Congress on Server and Data Centre Efficiency' added that these data centres had the potential to save up to $4bn in annual electricity costs through more energy efficient equipment and operations, and practices.

The orthodoxy is that data centre managers are anxious to control electricity bills, and keep costs down - both in terms of managing overheads and ensuring that they have a competitive offering to their clients for hosting, say. However, power use management does not always head up their lists of priorities. In many parts of the world power prices are stable and not the most painful aspect of overall expenditure. For instance, speaking to Network World earlier this year, Adam Gray, CTO of Santa Barbara-based IT services firm Novacoast, says escalating power costs are not a primary concern for the company's two data centres. "Energy efficiency is not a priority," he said. "Our priorities are support, hardware replacement, mean time between failures, cost and reliability. The power consumption cost is a very small percentage of our IT costs. But if we lost a server, that would be catastrophic." Energy efficiency is important, Gray acknowledged, but added that it didn't even "make our top five [concerns]."

That might change if data centre managers were the ones who had to foot the electricity bills. But research by Quocirca found that fewer than one in five IT decision makers have responsibility for the electricity bill, with 54 per cent never made aware of it. Given these figures, it is unlikely that greening can be wrought if managers have no access to the raw metrics that tell them roughly how much juice their systems are swallowing.

Most estimates of data centre energy consumption relate to power consumed by servers, and not the myriad other electronic devices found under its roof: getting these to run efficiently using less power is no doddle. In the wider IT context the same constraint applies. Network devices like routers and switches are also pulling on the power supply. Although progress is being made by vendors like Juniper to reduce the power needs of its core routers, it will be some years before energy-efficient data communications platforms predominate; what's more, expensive routers and switches have longer lifecycles than servers, and are less easy to swap-out for upgrade. 

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