CERN recorded 23 petabytes of data in 2011, and the flow is set to rise in 2012. To help respond to the challenge, CERN's IT department is participating in the Helix Nebula project, a public-private partnership to create a European cloud-computing platform.

"We're not replacing the Grid," says Bob Jones, responsible for CERN Openlab and EC-funded projects in IT. "We're looking at three complementary ways of increasing CERN's computing capacity, so we can continue to satisfy our users as demand goes up." Firstly, says Jones, the IT department is upgrading the computer centre's electrical and cooling infrastructure in order to increase the availability of critical IT services. The upgrade will also provide more floor space for servers in the area called The Barn. Secondly, CERN servers will be hosted in a remote data centre in another Member State, probably as soon as 2013. The location will be announced later this month.

"Thirdly," says Jones, "there's cloud computing with the Helix Nebula project. We're testing it using ATLAS simulation software and plan to expand the testing to more experiments in the future."

Cloud computing is a radically new way of providing computing resources. Instead of procuring the hardware and then maintaining and managing it, the IT department will procure the service from a commercial infrastructure provider within the Helix Nebula partnership, providing network access, storage and CPU. Jones says he likes the flexibility the system provides. "It's a pay-as-you-go scheme," he says. "You only pay for the resources you actually use."

Performance issues such as functionality and reliability will be tested in the first two pilot years of the project, and CERN will need to determine which legislation is applicable to cloud services not physically located on the CERN site. Along with two other international organizations involved - the European Molecular Biology Laboratory (EMBL) and the European Space Agency (ESA) - CERN will need to address confidentiality and privacy issues in relation to cloud computing. "EMBL and ESA deal with patient information and sensitive geophysical data, so they have additional security concerns," says Jones. "This is why the project serves as a testing ground, because it covers many different potential uses. When the various issues have been resolved the system should be fit to be rolled out to national institutes."