Inside the Commonwealth Bank data centre

CBA's longer term plans for its data centre presence appear to be to reduce its reliance on the space altogether.

At the very least, the Bank appears to be pursuing a strategy to convert capital expenditure in the data centre into an operating cost, by purchasing IT infrastructure and capacity from third-party providers where appropriate rather than buying more space and kit to do it themselves.

"We'd like to think that instead of our data centre requirements continuing to expand, we'd like to see them start contracting," Holdsworth said.

"We don't want to just rely on leasing, renting, buying or building data centre space to run everything. But in saying that, we'll still have a lot of things we want to manage internally."

As this suggests, Holdsworth is the first to admit it's not a model that will sustain all of the Bank's workloads, but it's one that CBA is currently exploring with its suppliers.

"More and more we say ‘why can't we buy infrastructure as a platform? Let's not buy and build it ourselves. Why cant we tell you we need capacity and load it in?'" Holdsworth said.

"I think suppliers are becoming much more receptive to those types of conversations."

Holdsworth said CBA continues to explore both public and private cloud-based computing services.

"We've done quite a lot of thinking around cloud but you've got to use the right tool for the right workload," he said.

"The type of workload you push to the cloud are things that don't have security clearance issues. They could just be really short bursts of a particular workload or you could place workloads in different places depending on the time of day or price of service.

"We're experimenting with that now".

CBA already runs compute capacity planning in its operations and has its outsourced providers bring storage and server capacity online up to three months ahead in anticipation of future demand.

"We try to keep a close eye on demand by forecasting it and trying to build out infrastructure at least two or three months ahead of forecast demand," Holdsworth said.

"Most of the providers we work with are happy to build out based on demand. [The other advantage is that] we only start paying for that equipment when we switch it on."