The rapid growth in data centres in the South East of England is being fuelled by the fact that business want their server farms nearby.

So says business continuity specialist, SunGard Availability Services, which has just announced a major investment in its UK infrastructure by expanding its data centre capacity in the South East.

SunGard said it is building a third data centre located in Woking, Surrey. This data centre known as TC3 will provide managed hosting services to businesses in the London area, and is expected to open its door on 12 March, 2009.

TC3 will be connected to both SunGard's original London Technology Centre (LTC) near Heathrow, and another data centre (TC2) in London Docklands. SunGard is also expanding its centres in Livingston, Scotland and Elland, Yorkshire.

"London is the hottest global data centre market," says Daniel Golding, VP and Research Director at Tier1 Research. "Providers are becoming increasingly creative in their efforts to provide high quality data centre and disaster recovery products to the UK and EU markets. Load balancing IT across multiple energy efficient and highly redundant data centres is typically the best method of achieving those aims."

But with the pressure on land and infrastructure in the South East, wouldn't it make more sense to build data centre in the North of England, or even Scotland? Apparently not.

"There are two simple answers to this," said Dave Gilpin, chief strategy officer at SunGard. "The first is that data centres have typically gone to where there is the highest amount of IT density (mostly in the South East of England, especially London)."

Gilpin believes that most data centres are being sited outside the London area, mostly in the West (i.e. Hemel Hempstead, Slough, Woking, Leatherhead, Farnborough).

"The second point is that people in London want their data centres nearby, they still want to touch it, and they still want to get access to it in a hurry if they need to," he added. "In the data centre industry they are called huggers (because they want to hug their kit)."

Gilpin also pointed out that there is a technical reason to keep data centres nearby. "There is a distance issue for high availability synchronous replication, which is limited to roughly 60 to 70 kilometres," he told Techworld. "Asynchronous replication has a much greater range."

Gilpin says that he was at a conference at couple of years ago, where delegates were pitched the idea of setting up their data centres in Iceland, where they could be powered entirely by renewable energy sources, because Iceland is rich in both geothermal and hydro-electric power.

"It never got off the ground because people still wanted to have emergency physical access to their equipment," he said. "However, the more modern the data centre is, the less this argument holds water, thanks to improved network management capabilities etc."

Gilpin was also candid about the issue of green IT in modern data centres. "The truth is, the best way to save power, is not to have it running in the first place," he said. "The best rule of thumb is to ask, 'guys, can we turn it off? And then, can we virtualise it?'"