28 TEST & MEASUREMENT
28 TEST & MEASUREMENT
Effective
management
Barry Shambrook , Consultant and Trainer in data centre design and management www . bicsi . org
The importance of power monitoring at rack level for data centre Facilities Managers
Rack monitoring solutions have been utilised in data centres for some time , usually incorporated in the PDU ( power distribution unit ) located in the rear of the IT cabinet . But sometimes this can be found in the flexible power cable leading from the power outlet located above or below the cabinet . The rack monitoring can be a single LED indication of the amps being drawn , or digital meters providing multiple parameters including voltage , power ( Watts or Volt Amps ), and energy use ( kW hours ) which can be gathered into a database and read remotely . The more sophisticated units can measure and report these parameters for each outlet socket of the PDU .
BICSI 002 Datacenter Design and Implementation Best Practices says , “ The ability to monitor power strip loads remotely via a centralized monitoring system is recommended for high-density and large-scale facilities .”
Rack monitoring is most commonly used by the IT data centre manager to monitor the power use per rack or item of equipment to assist with the management of rack power and cooling capacity power , in conjunction with space and network connectivity . Some organisations allocate IT equipment or whole racks to departments in order to allocate costs .
Rack monitoring is commonly considered part of the IT infrastructure , and the information generated is either not made available to the facilities team , or only in a limited reactive manner . This article considers the importance and benefits of complete and real-time monitoring information to the facilities team running the power and cooling to the data centre .
Correct reporting of PUE The Green Grid , a not for profit association that promotes energy efficiency in data centres , originally published the definition of PUE in 2007 . The Power Usage Effectiveness metric was initially total power consumed by the data centre , including that consumed by the facilities and the IT , divided by the power consumed by the IT alone . In 2012 this was clarified and refined to total energy consumed over a period of no less than 11 months divided by the energy consumed by the IT equipment over the same period . It was also separated into three categories depending on where the IT energy is measured . See the diagram on the next page .
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