On 29 June 2017, the CERN DC passed the milestone of 200 petabytes of data permanently archived in its tape libraries. Where do these data come from?  Particles collide in the Large Hadron Collider (LHC) detectors approximately 1 billion times per second, generating about one petabyte of collision data per second. However, such quantities of data are impossible for current computing systems to record and they are hence filtered by the experiments, keeping only the most “interesting” ones. The filtered LHC data are then aggregated in the CERN Data Centre (DC), where initial data reconstruction is performed, and where a copy is archived to long-term tape storage. Even after the drastic data reduction performed by the experiments, the CERN DC processes on average one petabyte of data per day. This is how the the milestone of 200 petabytes of data permanently archived in its tape libraries was reached on 29 June.

The four big LHC experiments have produced unprecedented volumes of data in the two last years. This…

IntroductionAre you ready for a new challenge?  Would you enjoy working on large-scale asset management platforms in one of the largest particle-physics experiments in the world?  If so, come and ...