Data management at CERN: current status and future trends

The European Laboratory for Particle Physics (CERN) straddles the Franco-Swiss border near Geneva. The accelerator that is currently in operation, LEP, entered service in 1989 and is expected to run until the end of the current millennium. The recently approved Large Hadron Collider, or LHC, which will coexist with LEP in the existing tunnel, is scheduled to start operation in 2004. This new facility will generate many or even many tens of PB of new data per year. Even the calibration and monitoring data will be in the 100 GB/year range! (Today, we have a few hundred TB of event data and 10-100 MB of calibration data.) We describe the evolution of the CERN-developed mass storage system originally built for LEP, the impact of the IEEE MSS reference model on this evolution, and our plans for the future. We also comment on the evolution, and state of the MSS reference model itself, and on response (or lack of response) from industry to the mass storage challenge that is facing many sites today.