In the ongoing battle against rising energy costs and climate change, servers have swiftly emerged as the frontline. According to Global Action Plan, an average server produces the same annual carbon footprint as a 4x4 that does 15 miles to the gallon.
As the benefits of energy conservation have come to the fore, manufacturers have taken advantage of new energy-efficient components from Intel, AMD and VIA to introduce a range of energy-saving servers, but how does an IT manager know which to choose?
"IT managers need to work with the vendor to see how much they'll save in terms of energy on the applications they run in their businesses and if those apps will work well on an energy-saving server," said Zahl Limbuwala, chair of the British Computer Society Data Centre Specialist Group.
"Unfortunately it isn't as simple as just choosing the energy-efficient solution, or even looking at total power consumption - there are other options open to businesses."
Virtualisation realityOne of those is virtualisation, currently the poster child of green IT, with analysts at Gartner describing it as the "most important IT technology for the next three years".
Virtualisation allows servers to act like multiple machines, each with their own OS and software, so companies need fewer physical servers in their datacentre, thereby reducing power consumption, carbon emissions and running costs.
And it isn't just for big companies: "Cost doesn't necessarily need to be a barrier to virtualisation. A number of hosting companies use open-source virtualisation products, so it's a proven technology," said Limbuwala. "In fact, there's rarely a case where virtualisation shouldn't be looked at as a possibility."
"Virtualisation will be everywhere soon," agreed the head of sales strategy at Fujitsu Siemens, Dave Pritchard. "You just need to look across datacentres in the UK: most are only operating at 15 to 20% of their capacity, meaning 80% is doing nothing.
"Virtualisation means you can get four machines onto one server, boosting efficiency, and in the future, as machines get faster, that's only going to improve. There could be ten virtual machines on one server soon, or more."
Pritchard also dismisses suggestions that putting so many virtual machines on one physical server is the IT equivalent of sticking all your eggs in one basket: "It's easier to make one machine disaster proof that an entire datacentre. It's easier to mirror for a start."
Beasts of burdenThe other benefit of server consolidation comes through the reduction of the burden factor - the associated energy costs of air conditioning, backup power and lighting, which Cisco estimates add an extra 1.8 to 2.5W to each watt used by a server. Reducing this leads to significant savings over time.
With the flurry of interest currently surrounding virtualisation, nearly every vendor has a virtualisation offering or partner. This means the technology can be configured on new hardware before shipping, smoothing the implementation for new businesses.
For those aiming to virtualise existing machines, there are numerous free open-source offerings, and all the leading commercial vendors offer trial versions of their software. This makes it easy for IT managers to experiment before deciding if the technology is right for their company.
Next: Refurbished serversIndex: How to make your business greenAuthor: Stuart Turton
How to make your business green: Servers