Citrix: the Virtual Route to Sustainable IT

“Consolidation saves money on space and power, but also on the servers themselves,” said Irwin. “Buying the servers will cost 60 to 70 percent less, and they are easier to manage, reducing IT costs.” The power saving can be more than double the savings from running the servers themselves – half the power of a normal server room goes on cooling. “Virtualization is economically more sustainable – and ecological as well,” said Irwin.

The main reason organisations have so many servers, is that till now each application has usually arrived with an expectation that it has a server, or a set of servers, to itself. “Typically, for most loads, the server is doing work ten percent of the time,” said Irwin. “Software vendors have said that when you deploy software, it needs its own server – and users have spent many thousands of euros on buying these servers.”

Virtualization can get that figure up to 40 or 60 percent utilisation, with five virtual servers on each physical server, which still leaves plenty of spare capacity, he calculates.

That cuts hardware costs – but what about power? Surely a server running at 50 percent will use more power? “Processors still clock through as if they are running at ten percent,” said Irwin.

There’s more to sustainability than reducing carbon footprint and costs, though: “A virtualised data centre provides a better service out to the rest of the business,” said Irwin. “Virtualization means you can move workloads to different servers, and users don’t see any downtime.”

“This makes companies more agile and flexible,” said Irwin. Instead of a prolonged period of provisioning, a virtualized data centre can spin up new server images when required, and retire old ones without having to recycle the hardware. So if a company should close or merge offices, or (as Citrix is doing) lay off workers, the IT department can reduce the IT provision more or less instantly.

“We now see the server as a resource for processing,” he said. “If it is running Linux workloads, they might move to different machines, or Windows workloads could be added to that machine.”

“The best time to consider virtualization is when you are looking at a server refresh,” he continues – and he believes companies should not put off refreshing their servers, even if money is tight. “Sweating assets doesn’t make sense. Modern processors get more MIPS (millions of instructions per second) for every Watt of power.”

Beyond virtualised datacentres, companies might find it’s even more sustainable to simply give up owning servers, he things. “Companies will look at moving their IT into the cloud, using services such as those offered by Amazon and Google – both built on Citrix’ Xen hypervisor.”

In the end, sustainable IT is not about cutting corners to save money, he said: “Sustainable IT is better IT. More uptime and lower costs.”