Storage Resource Sharing with CASTOR.
O. Bärring, B. Couturier, Jean-Damien Durand, E. Knezo, S. Ponce, Vitaly Motyakov · 2004
The Cern Advanced STORage (CASTOR) system is a hierarchical storage management system developed at CERN to meet the requirements for high energy physics applications. The existing disk cache management subsystem in CASTOR, the stager, was developed more than a decade ago and was intended for relatively moderate (large at the time) sized disk caches and request load. Due to internal limitations a single CASTOR stager instance will not be able to efficiently manage distributed disk cashes of several PetaBytes foreseen for the experiments at the Large Hadron Collider (LHC) which will be commissioned in 2007. The Mass Storage challenge comes not only from the sheer data volume and rates but also from the expected request load in terms of number of file opens per second. This paper presents the architecture design for a new CASTOR stager now being developed to address the LHC requirements and overcome the limitations with the current CASTOR stager.