Power is knowledge

Written by David Watkins, Service Delivery Director, VIRTUS Published 2016-08-16 08:13:00

It was the sixteenth century English scientist and statesman Francis Bacon who came up with the phrase ‘knowledge is power’. But he got it wrong.

Today, 390 years after Bacon’s death, we live in an age of sprawling IT estates that have a seemingly insatiable appetite for power. This has to be controlled.

Of course, you can only become energy efficient if you know how much of the stuff you consume in the first place. And so he who controls the power has the knowledge. Power is knowledge.

One of the techniques that has now become the de facto way for the data centre industry to measure its power usage is PUE. The Power Usage Effectiveness metric was devised in 2007 by The Green Grid, a global consortium of companies, government agencies and educational institutions which was setup with aim of making data centres and the enterprise IT ecosystem more energy efficient.

PUE compares the total amount of energy consumed by the data centre to the total amount of energy consumed by its IT equipment. The lower the rating, the more energy efficient the data centre.

In common with most operators, VIRTUS uses PUE ratings as a benchmark that describes how efficient its facilities are. The company’s innovative approach to cooling combines air-flooded data halls utilising hot aisle containment, with cooling delivered via indirect evaporative air technology. As well as leading to greater energy efficiencies and reduced carbon emissions, this also lowers costs.

The design of VIRTUS’ facilities in Enfield (LONDON1) and Slough (LONDON4) have PUE ratings of less than 1.5 and 1.25 respectively, whileLONDON2 in Hayes is less than 1.2 – not bad when you consider that one of the lowest PUE ratings for a data centre is currently reported at 1.07 for the Green IT Cube near Frankfurt.

But PUE has come under fire from some who say it has been hijacked by marketeers who are undermining its value by using it as a sales tool.

The metric has also been criticised by those who say that there are several other factors that influence power usage effectiveness such as a data centre’s geographical location, building construction, time of measurement, outside temperature, etc.

And lest we forget, PUE is actually a measure of how effectively power is used – not how much power is consumed.

So what’s the alternative to effective power measurement, management and control? Vendors such as Emerson Network Power, Nlyte, Schneider Electric and others believe the answer lies with data centre infrastructure management (DCIM) platforms.

These have been around for some time now and are designed to give engineers various controls over the entire data centre setup. This includes computing and network components, service delivery, quality assurance, as well as elements to help attain greener performance targets.
DCIM platforms can also include tools that allow environmental readings to be displayed graphically in real-time, enabling operation teams to adjust and recalibrate infrastructure as appropriate.

According to estimates cited in a white paper by Schneider Electric, a typical data centre today could house up to 30 per cent more IT gear using the same power and cooling if its capacity was properly managed.

The energy management specialist says anything more than 8kW per rack can be considered “high density”, and that fully populated racks of servers can draw from 6kW to 35kW per rack. But according to the company, most of today’s data centres are designed for a power density of less than 4kW per rack.
Schneider believes that an increasing number of operators are installing equipment that exceeds the design density of their facilities, resulting in stresses on power and cooling systems that can cause downtime from overloads, overheating and loss of redundancy.

“Most businesses cannot accept gross over-design or oversizing of data centres,” says the company. “The waste of capital and operating costs is significant.”

Consultancy firm McKinsey & Company agrees here. In a separate study carried out a few years ago, it found that on average, a data centre was only using 6-12 per cent of the electricity consumed powering its servers to perform computational operations. The rest was basically used to keep servers idling and ready in case of a surge in activity that could slow or blow operations.

McKinsey suggested that companies could double the efficiency of their data centres through more “disciplined management”. In particular, it said that companies need to manage technology assets “more aggressively” so existing servers can work at much higher utilisation levels.

While data centre infrastructure management can provide a solution here, take-up of such systems has been slow. DCIM proponents say there are various reasons for this – the perception that the systems are costly, the misguided notion that DCIM is really just about managing cable infrastructure, or a dismissive approach formed by the attitude that infrastructure management is a ‘nice to have’ but not necessarily at the top of the agenda.

But in reality, DCIM is a necessary part of the support solution a data centre operator should offer to its customers. VIRTUS provides a bespoke DCIM platform to all customers free of charge. This flexible solution provides a ‘single pane of glass’ view and can be built to meet a customer’s individual requirements ranging from high level power and environmental monitoring to detailed CPU, bandwidth, asset management and rack occupancy solutions.

In the future, some industry watchers reckon more radical infrastructure technology could take over from DCIM. For instance, they say artificial intelligence could be the game changer when it comes to managing data centre infrastructures. It’s reckoned AI could automatically balance cooling against load and let engineers know if anything is about to fail or needs maintenance without any need for human intervention.

But until such time, managing energy and power in the data centre will be left to bods rather than bots. And just a few weeks ago in mid-July, The Green Grid released a new metric which it claims will provide a broader understanding of a data centre’s cooling, and enable managers to take more informed decisions to maximise performance.

The organisation’s new Performance Indicator combines three key metrics: the PUE power ratio; IT thermal conformance; and IT thermal resilience.

According to The Green Grid, these metrics were developed to adequately reflect how equipment is cooled during normal operation, maintenance conditions, as well as failure scenarios to ensure that the assessed facility maintains its ability to house and protect IT equipment throughout its life.

It adds that by using these metrics, data centre operators will be able to visualise the impact of changes they make to maintain acceptable thermal performance, while improving energy efficiency.

And that’s got to be a good thing. After all, as Bacon once wrote: the desire of power in excess caused angels to fall.

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