By Stuart Corner
At its most basic, a data centre provides four services: a secure space to house your gear, power for your gear, cooling to remove excess heat and connectivity to the rest of the world. Beyond those basics there are many variables. We talk to industry experts to get the lowdown.
Space
The red room at NextDC S1 data centre in Sydney.
“At the end of the day an equipment rack is a rack” is one view of space in a data centre. However, the space equation can be more complex than that, according to Mark Deguara, senior manager of technical services for Australia and New Zealand with Emerson Network Power. He say because data centre operators are limited by two major constraints: floor space and total power available, they tend to charge more for the same space if the power density (kilowatts per rack or per square metre) is higher. However, higher density server technology is more power efficient, takes up less space and is cheaper for the same amount of processing power.
“A lot of data centres didn't use to charge according to power consumption, but that changed about five or six years ago,” Deguara says. “A centre may have 1000 square metres of space but they might have only a total of 10kW per square metre. So you might get the space cheap, but pay more if you want a high-power density.”
“One of the challenges for centres is how to accommodate everything from someone wanting 500 watts per rack right to 20 kilowatts.”
Power
IBRS adviser James Turner says demand for higher power densities represents a double whammy for the data centre industry.
"Data centres - especially older ones - face serious challenges in meeting their customers' power requirements while maintaining acceptable profitability," he says. "Newer data centres are being built with higher power density in mind, but these data centres need to be close to capacity for them to be operating at peak efficiency.”
According to Turner, the power usage efficiency of a data centre is critical and data centre providers should be asked to quote their PUE. This is the ratio of the total power consumed by the data centre to that available for computing equipment (the difference between these two figures represents the power used for cooling and for running the facility). The closer to 1.2 the better, according to the US-based Uptime Institute.
“In terms of power efficiency, the ideal is a well-designed, massive data centre that's fully stocked,” Turner said. “Given that power costs are unlikely to ever go down, it makes sense to take advantage of an environment that is as efficient as possible. I think anything lower than 1.6 is fine, and anything here in Australia that's claiming to be close to 1.0 is suspicious.”
Pricing
Despite the complexity of pricing around space and power densities, Mayank Kapoor, industry manager - data centre and cloud computing with Frost & Sullivan, says pricing has become much more transparent in recent years.
“It’s easy to compare costs across data centres on specific costs for rack/space rental, power, support, network and any connectivity services, but the comparison should be made across providers that offer similar service level agreements and guarantees.”
Security
Physical security and access control come high on the agenda, according to Adam Beavis, general manager of cloud services with Thomas Duryea Consulting. The company is both a customer and provider of data centre services: it rents space to support its own cloud services and also resells space.
Security is mainly about how access rights are managed, he says. “We've had a situation where one provider gave unauthorised access without following proper process. We expect our providers to follow the protocols and we put forward.”
According to Kapoor, “A policy/protocol outlining the access for staff and its requirements should be a part of the contract.”
Redundancy
The ability to provide power and cooling in the absence of mains power are the main redundancy issues and there are many ways of achieving this - not all equal. For Beavis, getting reports on maintenance and testing of back-up systems is important.
“Our supplier has a rolling maintenance schedule for back-up systems. They test them every month, and they send us a report,” he says.
Many customers choose to replicate their assets across multiple data centres, sometimes in different locations, to ensure they never have to do without their data and systems.
Customer service
This is increasingly becoming a key differentiator for data centres. According to Beavis, “The new centres that have come on stream in the last 12 months like NextDC have really taken that to the next level, allowing you to manage your racks on an iPhone app and order upgrades online.” He says dedicated account managers able to respond in a timely manner are an increasingly common feature.
Kapoor says NextDC “raised the bar with its ONEDC solution by offering real-time information on the status of the data centre at a rack level”.
Connectivity
Services from at least two carriers are necessary for redundancy and here independent data centres score over telco-owned facilities.
“The more the better, especially as we have a diverse set of customers,” Beavis says. “It's very important to have as many carriers possible. With telco-owned data centres, it can be difficult getting other providers in there. That's why we choose agnostic centres that are purpose-built to allow any provider to have access.”
Kapoor agreed, adding that customers might need multiple carriers in order to get optimal access to a particular regional or overseas location.
Location
CBD or near CBD locations are favoured because of better connectively and for customer access, for which demand was increasing, Beavis said. Offset against this is a minimum separation of 25 kilometres required by many customers for compliance purposes.
Occupational health and Safety
According to Turner, this is an often overlooked aspect of data centre operation, but one with potentially fatal consequences. He says IBRS is aware of incidents within data centres that had created a health and safety hazard, two of which could easily have resulted in death.