Too Hot to Handle

Data centers have a reputation for guzzling power, but in today’s energy-conscious world there’s no room for wastefulness.

In the US alone, data centers currently consume two percent of total energy production – the equivalent of half a dozen 1000-megawatt power plants. As the need to hold company data increases, data centers will continue to grow – seemingly without end. Worryingly, servers that consumed an average of 100 watts of power 10 years ago now consume an average of 400, with many wasting at least 60 percent of the energy they use. As the cost of energy continues to rise due to limited availability, IT managers find themselves in a difficult situation: how will they balance the need for bigger datacenters to accommodate their IT needs with fewer, potentially costlier power resources? Improving efficiency is the easiest answer.

Cooling equipment and powering the servers, storage and infrastructure required to support business applications are the biggest energy guzzlers in a data center. Managed services provider Atos Origin has several major data center operations, providing full 24/7 support for business-critical customer environments, and energy efficiency is at the top of the company’s agenda. According to Guy Lidbetter, the company’s CTO for Managed Operations, one of the most obvious routes to achieve better efficiency whilst limiting the impact on the physical infrastructure is consolidation and virtualization. “By merely looking at an optimization strategy using virtualization techniques, it is possible to increase the utilization capacity from around 20 percent to 60 percent,” he identifies. “Basic maths tells you that if you start at 20 percent and go to 60 percent, then you should be able to deliver the same amount of computer power through virtual machines rather than physical ones.”

Keeping things cool
A second way to better efficiency is rearranging the hot/cold aisle – particularly effective when it comes to improving cooling efficiency. After all, cooling accounts for 35 percent of data center energy consumption. “This is a very effective method,” enthuses Lidbetter. “Sometimes you might get a rack that can hold, for example, 16 servers or blades but you can’t put in more than 12 because of the amount of power it consumes at full capacity. It’s actually possible to seal off the aisles so they are totally enclosed. The heat is then taken upwards and outwards from the top.”

Although powering a ‘green’ data center may be a contradiction in terms given the amount of energy they use, even turning the set point up a few degrees can have a massive environmental impact. Changing the temperature of the center may be a small step, but could have a big impact and save as much as four percent in energy costs. Despite the advantages, some managers worry that upping the temperature might leave less time to recover from a cooling failure. Fortunately, there are a few radical technologies entering the industry that should make cooling less of a problem. One of these is fresh air-cooling. “This involves taking air from outside and conditioning it,” explains Lidbetter. “It dehumidifies the air, cleans out all the dust, cools it and then puts very clean air back into the data center environment. Taking air at 15 degrees from the ambient atmosphere outside could be enough to generate all the cooling you need inside the data center. You should need a lot less power, as you’re doing less conditioning to keep the data center at operating temperature.”

Water works
Water-based cooling is another method that can be adopted to make the data center greener. Companies have, in fact, been sluggish to accept the potential of liquid cooling despite the fact that even during the 1960s distilled water was being used by IBM to cool mainframe computers and in the mid-1980s over 90 percent of mainframes were cooled via water. Water’s cooling potential has undergone a renaissance in the last few years, and is set to continue in future. “10 years ago, the thought of water in a data center would have caused mass panic as the two don’t normally mix,” explains Lidbetter. “However, water is a much more efficient cooling agent than air at getting heat out.”

In years to come, Lidbetter sees options such as utility computing growing in popularity, providing access to data center resources over the internet without expensive investment in IT infrastructure. “This option allows for a shared IT infrastructure not just with one client, but with multiple clients on the same infrastructure,” he says. “Typically, today’s organizations, even when outsourced, have a dedicated infrastructure just for them. Therefore, even if we’re optimizing as best we can, we’ve still got multiple infrastructures from multiple clients. I see it being possible to consolidate this down into a shared infrastructure for multiple clients.”