CVMFS : CernVM-FS

The CernVM File System ("CernVM-FS" or "CVMFS") is a network file system based on HTTP providing a scalable end efficient software distribution service. It is used by Physics collaboration to deploy software on the worldwide-distributed computing infrastructure. Same versions of all software components are then available simultaneously in all sites.

CernVM-FS is implemented as a POSIX read-only file system in user space. Files and directories are hosted on remote web servers (Cern, CC-IN2P3...) and mounted in the universal name space /cvmfs. In order to minimize network and disk usage, files and file metadat are cached and downloaded on demand.

Starting from the base directory /cvmfs, different repositories are identified by fully qualified names (such as atlas.cern.ch, sft.cern.ch, lsst.opensciencegrid.org, cta.in2p3.fr, dirac.egi.eu...) and are mounted automatically just by accessing them.

At any time, one can probe a repository to check ressources are available on CVMFS :

$ cvmfs_config probe lhcb.cern.ch for LHCb Software

$ cvmfs_config probe oasis.openscience.org for IGWN Software

Accessing file system $ ls /cvmfs/lhcb/cern.ch

The following repositories are available in READONLY from the LAPPUI/LAPTHUI and LAPPUSMB machins as well as from all computing nodes of the MUST bath farms :

/cvmfs/atlas.cern.ch
/cvmfs/atlas-condb.cern.ch
/cvmfs/lhcb.cern.ch
/cvmfs/geant4.cern.ch
/cvmfs/sft.cern.ch
/cvmfs/grid.cern.ch
/cvmfs/ilc.desy.de
/cvmfs/cta.in2p3.fr
/cmfs/lsst.in2p3.fr
/cvmfs/lsst.opensciencegrid.org

Access to the documentation : https://cvmfs.readthedocs.io/en/stable/index.html