Behind all the ‘software-defined this’, and ‘cloud-enabled that’ is a world of electrons and degrees Celsius that keeps it all ticking over. This is the world of critical infrastructure. It’s a world that we conveniently ignore because, the vast majority of the time, it just works.
In this article, we take a peek inside the lights-out data centre to highlight what it is, how it works, and the way it’s changing. We also point out some ways that systems integrators can take advantage of the changes taking place, and ensure they stay relevant into the cloud era.
For all the breathless language surrounding cloud computing, the reality is that the cloud consists of servers and networks installed inside buildings. They need power to stay alive, cooling so they don’t melt, and locks so they aren’t stolen.
Getting these foundational technologies right is an important part of the way modern technology runs. For a start, these are large capital investments, six and seven figures large, at least. With this sort of money at stake, quite a bit of care is taken to ensure the design is right. But customers often don’t get to see the details of these designs, so how can you really know if a data centre is well designed?
Bob Sharon, chief executive of consultancy Green Global Solutions, recommends a strong rating system like NABERS – the National Australian Built Environment Rating System. “The NABERS rating is a thing to ask for,” he says. “You know that the measure is true and correct. The numbers for PUE (Power Usage Effectiveness) are challenging to get right.”
Sharon’s view is shared by many in the industry, and there is a general trend away from using PUE numbers as a selling point. However, NABERS requires a minimum of one year of data collection, so not many newer data centres have been operational long enough to have a rating yet.
Sharon also recommends the Uptime Institute’s tier rating system. “The TIA-942 standard is a great checklist model for the design of a data centre, but Uptime Institute certifications also take operations into account.”
A key part of data centre design is airflow management. How air moves around a data centre is the key to keeping it cool, and there have been big changes in airflow management in recent years. “You have to have hot and cold air separation,” Sharon says. “If there’s no separation, there’s a problem before you start.”
At NextDC’s Sydney facility, the entire under-floor area is filled with cold air, maintained at positive pressure. Shuttered floor vents allow cold air to flow into small, fully enclosed areas connected to the front of customer racks, in a hot-aisle/cold-aisle configuration. “Facility rules require customers to blank out unused rack units,” explains Steve Martin, NextDC’s general manager of partnership strategy, “so the only place the cold air can go is through the kit. Pressure keeps the flow even at different heights of the rack.”
The NSW government’s GovDC sites in western Sydney and Unanderra are prime examples of fresh air cooling, using highly filtered fresh air with the evaporation of water from a wetted matrix material, backed up by more traditional mechanical cooling.
The air also needs to be kept clean. Tim Gentle, general manager of Australian IT Services Group, tells CRN that the air circulating within modern data centres is carefully filtered. Some centres supplement cooling systems with free air cooling, mixing outside air with the hot return air, so it’s important to keep dust particles to a minimum. Even so, dust can still get into the centre. “A lot of the dust will settle, into corners, even onto equipment,” Gentle says. “The issue is when it gets disturbed, because then the dust will get into things. We have special filters on our vacuums that help prevent the buildup in the first place.” Few facilities managers want to trust the cleaning of sensitive equipment to office cleaning firms, which is where specialist firms like Australia IT Services come in.
Anyone going into a secure facility like a data centre needs to be appropriately cleared. “Most data centres just want a standard police check,” says Gentle, “but some of the government agencies do their own checks, including negative vetting.”