Data center efficiency-Is it size dependent?

Data centers for a long time have taken their own stand when questioned about the efficiency of operations. Some data centers follow the conventional methods of strategy implementation while the others take a different route. For example, Google has adopted custom built servers and batteries, Facebook uses a unique evaporative cooling method to save power, and Yahoo has adopted an outdoor cooling design. Data centers can be generally divided into two primary classes based on size that is the large data centers and the small data centers. Large data centers have an inherent advantage in implementing energy efficient strategies as they can shift operations to another facility as and when the situation demands. It could be a failure in the data center or an expansion plan adhering to all energy saving norms. “Large centers can operate at a higher risk of failure with the offset, but smaller data centers can't do that as easily,” said Fluegeman, who specializes in facilities, power and cooling, and is also the principal engineer with PlanNet Consulting. “It’s following the sun or the moon, because they can very easily shift their traffic to different locations depending on whether it's night or day in a particular location,” he said. “Especially if you're using outside air and free cooling or air-side economy as it's called, this is a concept that's used to some degree by larger companies with data centers worldwide, where they shift traffic.” In the case of smaller data centers (data centers that lack the infrastructure and resources of its larger counterparts) energy efficiency strategy implementation along with reducing costs is a difficult task. So how does one cope with such a scenario? According to Fluegeman, three quintessential parameters to be followed by a small data

center are- Design of the IT structure: it is essential to design the data center in a way that it helps in consolidation of the files. For example using file duplication or compression. This would automatically reduce the amount of space required for the storage of files. Enterprises can modify or make alterations to the network configurations from their own data centers as well as allowing the users to access data from anywhere at any time. “There are ways to architect your system to deal with duplication and keep things lean and mean and trim with good housekeeping,” he said. “This allows data centers to be smaller and greener by using as little power as possible.”

Tiered storage can be used as another remedial measure: with this files are stored in servers, and the servers run on sleep mode. The files can be pulled up or retrieved only when necessary, thus saving a lot of power. Restructuring the cooling method: It is imperative that small scale enterprise data centers make use of hot and cold aisle containment for data center cooling. This is to ensure that hot air is isolated from the cold air. But the crucial aspect of this design is to keep the hot air from nixing with the cold air. This would create a 30 degree difference in the temperature of the data center, says Fleugeman. One way is to line up the servers such that the front faces one direction and the exhaust side faces the back. This forms the hot aisle and the cold aisle. Another way of doing this, in case of parallel arrangement of servers is to stack servers with alternate hot and cold aisles. Front faces of two servers face each other while the back faces the front of another line of servers Use uninterrupted power supply to reduce excessive power costs: The use of the UPS is a radical transformation in the deployment of energy efficient measures. UPS is normally used when there is a power outage, but this can be prove to be an advantage for data centers as UPS wakes up from the sleep mode only when the power fails. The difference in power drop and the UPS turning back on is so minimal that the equipments fail to pick up the drop in power and continue to operate continuously. Switching to higher voltage equipments can result in a lot of power savings since it is more efficient and the physical conductors are smaller. “If you look at power lines on big poles on the hill side, those wires are small- they're far apart, but the power voltage is very high,” he said. “This is being applied to data centers now. Higher voltage is slightly more dangerous and in the U.S we have a lot more attorneys. That's what keeps voltage lower, in my personal opinion.” Data Center Talk updates its resources everyday. Visit us to know of the latest technology and standards from the data center world. Please leave your views and comments on DCT Forum