Computer Centre Upgrade for LHC Computing

In mid-1999 it became evident that the computer centre infrastructure could not meet the power and space requirements of the offline computing farms for  the LHC experiments. At that time, LHC startup was scheduled for 2006 and the farms were expected to occupy around 2,000m² and to need an electrical supply of 2MW.

After an initial review of the 30-year old B513 infrastructure, visits to other computer centres and working with a computer centre consultancy, Tony Cass and Anne Funken developed a plan to

• increase the available floor area by redeveloping the tape vault,
• provide a new substation to upgrade the available power and to provide appropriate protection against power failures (as CERN's diesel generators cannot support the full load), and to
• upgrade the electrical distribution capacity in the existing machine room.

Detailed planning of the vault redevelopment started in mid-2001 and the conversion work is now almost complete. Once the new space is available, expected to be at the end of September 2002, equipment will be migrated from the machine room allowing work to start there in mid-2003. Detailed planning for the substation is now underway (July 2002).

Since the project was first started, the start date of LHC has been pushed back to April 2007 and the size of the computing farms has been revised downwards. The power requirements for the TIer0+Tier1 facility at CERN is now estimated at 1.5MW. This still exceeds the capacity of the current infrastructure, however, and so most of the design work remains valid. The key exception is in UPS capacity where we are investigating ways in which to build up UPS capacity between 2004 and 2008 rather than installing all capacity in 2004.