Mar 21 – 27, 2009
Europe/Prague timezone

CernVM - a Virtual Software Appliance for LHC applications

Mar 26, 2009, 2:00 PM
Club A (Prague)

Club A


Prague Congress Centre 5. května 65, 140 00 Prague 4, Czech Republic
oral Software Components, Tools and Databases Software Components, Tools and Databases


Predrag Buncic (CERN)


CernVM is a Virtual Software Appliance to run physics applications from the LHC experiments at CERN. The virtual appliance provides a complete, portable and easy to install and configure user environment for developing and running LHC data analysis on any end-user computer (laptop, desktop) and on the Grid independently of operating system software and hardware platform (Linux, Windows, MacOS). The aim is to facilitate the installation of the experiment software on an user computer and minimize the number of platforms (compiler-OS combinations) on which experiment software needs to be supported and tested thus reducing the overall cost of software maintenance for LHC. CernVM Operating System, based on rPath Linux, fits into a compressed file smaller than 100 MB and represents a common platform that can host software frameworks of all four LHC experiments. The experiment software stack is brought into appliance by means of CVMFS, a file system specifically designed for an efficient and ‘just in time’ software distribution. In this model, the client downloads only necessary binaries and libraries as they get referenced for the first time. By doing that, the amount of software that has to be downloaded in order to run the typical experiment tasks in the Virtual Machine is reduced by an order for magnitude. In this contribution we describe the architecture and implementation of CernVM and CVMFS as well as plans to evolve CVMFS into content delivery network using combination of P2P and HTTP protocols. The CernVM project, which has started at the beginning of this year is funded for period of four years under the recently approved R&D program at CERN.

Primary author


Carlos Aguado Sanchez (CERN) Jakob Bloomer (Univ. of Karlsruhe) Leandro Franco (CERN) artem Harutyunyan (Yerevan Physics Institute) pere Mato (CERN)

Presentation materials