CERN Accelerating science

We are pleased to announce the next release Castor, V 1.4.1, on June 13 in ASIS and will contact all experiments soon after that date to upgrade their servers (stagers). The stager upgrade itself will be a minor one compared to the current version and we would very much appreciate the collaboration of all experiments to accept this upgrade soon after June 13 and in any event before June 22.

The specific enhancements of this release will be:

• Support for writing more than 10k files on tapes (with a new tape label AUL).
• Improved security.
• An internal monitoring framework.
• Preparation for the eventual removal of the Tape Management System. Experiments should note however that developments in this Castor version have allowed us to relax the time-scale for the removal of TMS which had been the end of 2002. Nevertheless we continue to ask that experiments move away from TMS by the end of 2003.
• Preparation for a facility that will permit the re-packing of CASTOR tapes (e.g. removing 'holes' due to deleted files). This will also be useful for condensing tapes written on the current STK 9940 drives to the higher density of the new 9940 drives that we hope to obtain for production towards the end of the year. The improved density and transfer speed will permit a substantial savings on media costs in the future.
• Preparation for the automatic refill of tape pools.
• Bug fixes.

The new client introduced with the ASIS release will co-work with the current stager.

The main CASTOR developments for the rest of 2002 are expected to concentrate on the following areas:

• Optimization of the hardware and software components of CASTOR in order to meet the requirements of the LHC Mock data challenges. This work, done in collaboration with ADC group, pushes the limits of performance of CASTOR and ultimately benefits all users.
• Implementation of a 'fair-shares' allocation system for tape drives which will prevent single users and/or groups from 'hogging' all available tape drives.
• Improved statistics that should permit experiments to better understand the use of their CASTOR data in order to better organize their data in the CASTOR disk pools and to reduce tape mounts.
• Support for file sizes bigger than 2GB (64 bit support) in collaboration with IN2P3.
• Development of a 're-pack' facility to copy tapes to higher density media while removing files that have been logically deleted.
• Implementation of 'safe' copies of user tapes. Such copies would normally not be read but rather be a backup for important user files. For financial reasons this will have to wait until the introduction of the higher density 9940 drives.
• Redesigning the CASTOR stager into modular functional units that will provide a more scalable solution. The current stager, much modified since the SHIFT era, is badly in need of a rewrite. The implementation phase is not expected to be completed this year.
• Improvements in the robustness of CASTOR by extending the internal monitoring system to be more pro-active when problems are detected.
• Work will start on a GRID interface that accepts GLOBUS certificates and publishes MSS/HSM information to the GRID.