Skip to content

CVMFS

CVMFS (CernVM-File System) is a software distribution service heavily used by High-Energy Physics (HEP) experiments to deliver software to multiple different computing systems worldwide. It presents remote software pulled over http as a POSIX read-only file system in user space (normally using FUSE). Access is performant and scalable due to multiple levels of caching such as a local file cache and squid web caches.

CVMFS at NERSC

The CVMFS filesystem is accesible at /cvmfs and can be accessed from any login node or compute node. The current list of supported repositoitories is listed below. If you need a repository added please reach out at help.nersc.gov.

nersc$ ls /cvmfs
alice.cern.ch
alice-ocdb.cern.ch
ams.cern.ch
atlas.cern.ch
atlas-condb.cern.ch
atlas-nightlies.cern.ch
cernvm-prod.cern.ch
cms.cern.ch
config-osg.opensciencegrid.org
cvmfs-config.cern.ch
dunedaq.opensciencegrid.org
dune.opensciencegrid.org
fermilab.opensciencegrid.org
gm2.opensciencegrid.org
grid.cern.ch
icecube.opensciencegrid.org
larsoft.opensciencegrid.org
lhcb.cern.ch
lhcb-condb.cern.ch
lz.opensciencegrid.org
minerva.opensciencegrid.org
mu2e.opensciencegrid.org
nova-development.opensciencegrid.org
nova.opensciencegrid.org
oasis.opensciencegrid.org
sft.cern.ch
sft-nightlies.cern.ch
spt.opensciencegrid.org
sw.lsst.eu
uboone.opensciencegrid.org
unpacked.cern.ch

CVMFS in Containers

If using shifter you should specify the --modules=cvmfs flag to shifter to make that mount appear inside your container (unless you want to use your own version of cvmfs inside the container).

nersc$ shifter --module=cvmfs

You can also use the new container runtime podman-hpc with CVMFS by mounting the /cvmfs directory into the container.

nersc$ podman-hpc run --rm -it -v /cvmfs:/cvmfs container:tag

CVMFS Batch Jobs

You can also load this module in your batch script and you should also add the cvmfs file system license -L cvmfs which would allow us to pause your jobs from running if the cvmfs mount was unavailable

1
2
3
#!/bin/bash
#SBATCH --module=cvmfs
#SBATCH -L cvmfs