Is energy management software the answer to data center managers’ power woes?
Data center energy management vendors claim that their tools can help ferret out scarce power and cooling resources, and at least one early adopter thinks it can take him one step further and validate his recommendations to upgrade servers and rethink cooling strategies.
Stan Cox is senior global data center manager at storage equipment manufacturer NetApp in Sunnyvale, Calif., and currently relies on an internally developed power calculator to manage his facility. The system collects aggregate power consumption data from the facilities department, estimates on device nameplates and data gathered by circuit meters at its co-location provider. The resulting model is pretty good, but not good enough.
“It’s a guesstimate, which is good enough when I have a brand new data center with nothing plugged in,” said Cox. “I need to know down to the kilowatt what I can actually install.”
Cox said he wants to be able to see power consumption for specific devices, and then use that data to trend and forecast his needs. Unfortunately, the power consumption data listed on a device’s nameplate is totally inadequate -- sometimes off by about 65%.
“If I were to manage by nameplate, I’d be out of data center space in a week,” he said.
One promising -- and more accurate -- energy management tool is Power Assure EM/4, which Cox said looks like it will cost less than many of its competitors, and which can poll devices using out-of-the-box tools like SNMP rather than expensive intelligent power distribution units (PDUs).
The case for hardware upgrades
Finding available space and power to bring new systems online is a constant juggling act. When Cox began at NetApp three years ago, the Sunnyvale data center only had 10 kW of power available and 165 projects scheduled for that year. Things are better now, thanks in part to advances in hardware energy efficiency and consolidation, but it can still be a hard sell to convince application owners to migrate off old, energy-inefficient servers, he said.
The company operates on a 36-month lease cycle, but not all application owners are ready to migrate their systems then, and often request lease extensions. Systems that have been virtualized are easier to move, but that’s not all of NetApp’s applications.
“Right now, we’re not mature enough with virtualization to be able to say, ‘Here, we’re just going to Vmotion you off on to this new box,’” Cox said.
To that end, Cox is excited by Power Assure EM/4’s ability to assign a dollar amount to a server based on its energy efficiency, which he hopes will help convince reluctant IT owners to agree to migrate onto newer hardware.
Settling on a set point
Power Assure EM/4 has also been instrumental in helping NetApp optimize its cooling. For example, following new ASHRAE guidelines that give the green light to warmer center temperatures, NetApp raised its data center set point to 78 degrees only to find that its energy consumption actually increased.
“When we raised the set temperatures, the machines say ‘Hey, I’m running a little warm here’ and the fans turn on,” Cox said, explaining the increased energy use. Since noticing that, NetApp found that the threshold at which point server fans turn on is about 74 degrees -- warmer than its old set point, but several degrees cooler than the ASHRAE guidelines.
Energy management could also help NetApp determine its containment strategy. Currently, the firm uses both hot-aisle and cold-aisle containment, but without access to the data, it’s hard to gauge which is more effective, Cox said.
Energy management uptake
Despite all the apparent benefits of data center energy management software, and the umbrella data center infrastructure management (DCIM) genre, uptake is moderate, said Julius Neudorfer, CTO at North American Access Technologies, a data center design and consulting firm in Hawthorne, N.Y.
“If you start doing energy monitoring down to the outlet level, it gets expensive very quickly,” he said.
While newer servers typically report on power consumption, older equipment may not, and getting that information requires meters to be installed at different points in the infrastructure.
“A big problem with these tools is retrofitting production data centers with sensors after the fact,” Neudorfer said. “Putting in monitoring points can be intrusive because it causes some downtime -- and it’s costly.”
Furthermore, data center energy management tools are still emerging, and the vendor landscape has yet to consolidate. Players include software vendors Power Assure, Modius and Sentilla, but established data center infrastructure players like Eaton, Schneider Electric and Emerson Network Power are also getting into the act through acquisition, Neudorfer said.
“They saw the sales piling up and they had nothing to sell against them,” he said.
Today, Neudorfer estimated that only 10% to 15% of enterprise data centers have some sort of energy management tool in place, be it third-party or internally developed. But that could be about to change, he said. “The people that have looked at basic monitoring functions may now be evaluating the next level of product.”