Multi-Petabyte Data Distribution in Industry & Science with CernVM File System
CVMFS
## CVMFS install party + adoption Q&A (BOF) [](https://fosdem.org/2026/schedule/event/W93GZR-cvmfs-install-party/)
Event:
## Open Source at CERN stand @ K level 1 (group A) 
### Software distribution in HEP  
## Lazy-pulling
container images
Lazy pulling in action
Normal image pulling
## References [doc](https://cvmfs.readthedocs.io/en/stable/cpt-containers.html), KubeCon25 [slides](https://static.sched.com/hosted_files/kccnceu2025/f3/ImageSnapshottersForEfficientContainerExecutionInParticlePhysics.pdf), [video](https://www.youtube.com/watch?v=Dc6S4vU9GiM)
cvmfs-posix-tools
cvmfs_
chgrp
cvmfs_
chmod
cvmfs_
chown
cvmfs_
insert
cvmfs_
ln
cvmfs_
mkdir
cvmfs_
rm
cvmfs_
rmdir
cvmfs_
rsync
cvmfs_
setfacl
cvmfs_
touch
## Changing contents,
the usual way * `cvmfs_server transaction` * make changes * `cvmfs_server publish`
Publish command in action
cvmfs_server transaction
change overlayfs mode
cp bigmodel.gguf /cvmfs/my.repo
copy to scratch area
cvmfs_server publish
copy to primary storage
cvmfs_rsync in action
## cvmfs-posix-tools:
under the hood - uploads all the new files to S3 directly - pushes metadata changes to CVMFS Gateway host - waits for new CVMFS revision to become visible
## References Container Images and CVMFS:
[doc](https://cvmfs.readthedocs.io/en/stable/cpt-containers.html), KubeCon25 [slides](https://static.sched.com/hosted_files/kccnceu2025/f3/ImageSnapshottersForEfficientContainerExecutionInParticlePhysics.pdf), [video](https://www.youtube.com/watch?v=Dc6S4vU9GiM) cvmfs-posix-tools: [pull request](https://github.com/cvmfs/cvmfs/pull/3964)
Q & A
Georgios Christodoulis, CERN
georgios.christodoulis@cern.ch
Andriy Utkin
hello@autkin.net
Open Source at CERN
## CVMFS install party + adoption Q&A (BOF) [](https://fosdem.org/2026/schedule/event/W93GZR-cvmfs-install-party/)
Event:
## Open Source at CERN stand @ K level 1 (group A) 
## Backup slides TODO