It's all change at the Computer Centre

The IT and EN Departments are modernising the infrastructure of the Computer Centre to improve the conditions in which the equipment has to operate and to increase capacity. The construction work has already begun and is due to be completed in October 2012.


Every year CERN experiences around ten power cuts lasting from less than a second to several hours. In most cases the two protection systems - the UPS* and the diesel generators – are able to ensure that the operation of the Computer Centre is not affected. As Vincent Doré, the project leader for the IT Department, and Paul Pepinster, the EN Department's technical coordinator in charge of modernising the infrastructure, explains: "Building 513 has two types of computing facilities – the "non-critical" ones, such as the servers for "off-line" computing, which have UPS systems ensuring that they can operate for 10 minutes after a power cut, and the "critical" ones, such as the computer network infrastructure and the databases used by the administrative services, which are connected to emergency diesel generators on the Meyrin site as well as to UPS systems. These generators can supply critical equipment with emergency power for a longer period than the UPS systems."

At present, in spite of these back-up systems, the operation of the critical installations cannot always be guaranteed in the event of an extended power cut, especially when outdoor temperatures are high. The infrastructure is therefore being enhanced to ensure that all critical computing facilities remain running 24 hours a day, 365 days a year. The EN and IT Departments have decided to create a special new room for the critical servers within the Computer Centre. The room will be powered and cooled by new secured, dedicated equipment, and the basement will be extended to house the new cooling system.

Today, all the critical and non-critical computers in the Centre are cooled by the same cooling units, most of which are positioned on the roof of Building 513. "As part of the modernisation project, we will separate the cooling systems according to the type of installation, for optimum operation: the critical systems will be cooled by new air-conditioning equipment installed in the new basement extension, while the non-critical systems will remain connected to the existing cooling units," explains Paul Pepinster.

The project also involves increasing the power capacity of the Centre from 2.9 MW to 3.5 MW, which will allow some 2,400 new computers to be housed there. "Today, the Computer Centre comprises around 10,000 servers, which corresponds to a power consumption of 2.5 MW. In the coming months we will be increasing the number of computers by 1,600, which would push the Centre's capacity to the limit. The work that's just started will not only improve the back-up systems for the critical facilities but will also allow us to host an additional 2,400 computers, increasing our computing capacity by 20%," explains Vincent Doré.

In parallel with the modernisation of CERN's facilities, the critical computing systems are being decentralised to avoid problems during power cuts. "Part of the system that manages CERN's electronic mail has already been moved to a hosting facility in Geneva. We are now working on a plan to distribute other computing services across different geographical locations," confirms Frédéric Hemmer, Head of the IT Department.

In addition to the EN and IT Departments, the project will call on the GS Department for the civil engineering and improvements to the building's safety systems. While the work is in progress, almost 60 parking spaces around Building 513 will be temporarily out of use due to the worksite. We apologise to users of the Computer Centre and Restaurant No. 2 for the inconvenience.

*an uninterruptible power supply.

Did you know?

In the event of a power cut, the temperature in the Computer Centre can increase by 3 to 5 degrees per minute in certain cases. The operator in charge has three minutes to shut down all non-critical systems if he considers it a necessary precaution to prevent the critical systems from malfunctioning.


by Laëtitia Pedroso