Metrics and monitors key to data centre power saving plans
Many data centre managers have yet to turn on the energy measurement and monitoring tools they need to kick start power consumption reduction initiatives and begin driving down the energy bill.
The observation comes as Gartner revealed that as many as 48% of data centre managers have apparently still not even considered the issue of energy management metrics.
“Without metrics it is impossible to get accurate data,” the analyst firm said of findings of a study announced today, “which is essential to evaluating basic costs, proportioning these costs to different users and setting policies for improvement.”
Gartner said that energy management both in terms of capacity and cost can only be effective through advanced monitoring, modelling and measuring techniques and processes.
The analyst group has urged organisations not to rely on internal metrics, saying that evaluating server energy needs to be done in an open and transparent manner.
It recommends the use of the SPECpower benchmark to evaluate the relative energy efficiencies of the servers.
Bodies like the Green Grid are active developing and refining additional metrics such as Power Usage Effectiveness (PUE) and its reciprocal, data centre infrastructure efficiency (DCiE), which enable data centre operators to estimate the energy efficiency of their data centres, compare the results against others, and determine where any energy efficiency improvements need to be made.
Other measures have been proposed like the site infrastructure power overhead multiplier, which is the ratio of data centre power consumption at the utility meter over the total hardware power consumption at the plug for all IT equipment. It is intended to give data centre engineers and managers a good idea of the energy-efficiency maintained by assets such as UPS, heating and light.
Companies like server power management supplier Raritan produce monitoring software, such as is used for its rack power distribution units. This can give data centre managers all they need to be able to determine their energy costs, right down to the server and application level.
Tracking and displaying power at the IT device level in this way is seen as one way of laying down the groundwork for improvements in capacity management and energy efficiency.
The conclusions of this latest research echo earlier findings from Forrester Research, which suggested that efforts to introduce energy efficient data centre policies were hampered because they can be at odds with the key performance indicators traditionally used to measure IT efficiency.
The analyst firm also said that in many companies the IT department neither sees nor pays the electric bill, and therefore lacks the incentive to save energy.
Gartner recommends that data centre managers use sensors to monitor potential hotspots, develop a dashboard of data centre energy-efficient metrics, and improve the use of the existing infrastructure through consolidation and virtualisation before building out or buying new/additional data centre floor space.