Getting started with EESSI

Using EESSI on our servers

Just load the ESSI module with preferred toolchain.

$ module avail ESSI
------------------------- /opt/software/custom/modules -------------------
EESSI/2023.06 EESSI/2025.06

$ module load EESSI/2025.06 
Module for EESSI/2025.06 loaded successfully
$ module overview

Installation for single clients

Ubuntu/Debian:

# Installation commands for Debian-based distros like Ubuntu, ...

# install CernVM-FS
sudo apt-get install lsb-release
wget https://cvmrepo.s3.cern.ch/cvmrepo/apt/cvmfs-release-latest_all.deb
sudo dpkg -i cvmfs-release-latest_all.deb
rm -f cvmfs-release-latest_all.deb
sudo apt-get update
sudo apt-get install -y cvmfs

# install EESSI configuration for CernVM-FS
wget https://github.com/EESSI/filesystem-layer/releases/download/latest/cvmfs-config-eessi_latest_all.deb
sudo dpkg -i cvmfs-config-eessi_latest_all.deb

# create client configuration file for CernVM-FS (no squid proxy, 10GB local CernVM-FS client cache)
sudo bash -c "echo 'CVMFS_CLIENT_PROFILE="single"' > /etc/cvmfs/default.local"
sudo bash -c "echo 'CVMFS_QUOTA_LIMIT=10000' >> /etc/cvmfs/default.local"

# make sure that EESSI CernVM-FS repository is accessible
sudo cvmfs_config setup

RHEL/Fedora:

# Installation commands for RHEL-based distros like CentOS, Rocky Linux, Almalinux, Fedora, ...

# install CernVM-FS
sudo yum install -y https://cvmrepo.s3.cern.ch/cvmrepo/yum/cvmfs-release-latest.noarch.rpm
sudo yum install -y cvmfs

# install EESSI configuration for CernVM-FS
sudo yum install -y https://github.com/EESSI/filesystem-layer/releases/download/latest/cvmfs-config-eessi-latest.noarch.rpm

# create client configuration file for CernVM-FS (no squid proxy, 10GB local CernVM-FS client cache)
sudo bash -c "echo 'CVMFS_CLIENT_PROFILE="single"' > /etc/cvmfs/default.local"
sudo bash -c "echo 'CVMFS_QUOTA_LIMIT=10000' >> /etc/cvmfs/default.local"

# make sure that EESSI CernVM-FS repository is accessible
sudo cvmfs_config setup

Now you can load the EESSI environment module:

source /cvmfs/software.eessi.io/versions/2025.06/init/bash

Then list all available modules (software):

{EESSI/2023.06} kjetba@UIO-laptop:~$ module avail

------------------------------------------------ /cvmfs/software.eessi.io/versions/2023.06/software/linux/x86_64/intel/haswell/modules/all ------------------------------------------------
   Abseil/20230125.2-GCCcore-12.2.0                   hatchling/1.18.0-GCCcore-12.3.0                     OTF2/3.0.3-GCCcore-13.2.0
   Abseil/20230125.3-GCCcore-12.3.0                   hatchling/1.18.0-GCCcore-13.2.0           (D)       p11-kit/0.25.3-GCCcore-12.3.0
   Abseil/20240116.1-GCCcore-13.2.0            (D)    HDBSCAN/0.8.38.post1-foss-2023a                     Pandoc/3.6.2
   acpype/2023.10.27-foss-2023a                       HDF/4.2.15-GCCcore-12.2.0                           Pango/1.50.12-GCCcore-12.2.0
   aiida-core/2.7.2-foss-2023a                        HDF/4.2.16-2-GCCcore-12.3.0                         Pango/1.50.14-GCCcore-12.3.0
   aiida-shell/0.8.2-foss-2023a                       HDF/4.2.16-2-GCCcore-13.2.0               (D)       Pango/1.51.0-GCCcore-13.2.0                             (D)
   aiohttp/3.8.5-GCCcore-12.3.0                       HDF5/1.14.0-gompi-2022b                             PAPI/7.1.0-GCCcore-13.2.0
   AITW-microstructures/1.0.0-foss-2023a              HDF5/1.14.0-gompi-2023a                             parallel/20230722-GCCcore-12.2.0
   AITW-stiffness/1.0.0-foss-2023a                    HDF5/1.14.3-gompi-2023b                   (D)       parallel/20230722-GCCcore-12.3.0                        (D)
   AITW-viscosity/1.0.0-foss-2023a                    HeFFTe/2.4.1-foss-2023b                             paramiko/3.2.0-GCCcore-12.3.0
   ALL/0.9.2-foss-2023a                               HepMC3/3.2.6-GCC-12.3.0                             Paraver/4.11.4-GCC-12.3.0
   .......

More info on how to use modules here.

Official install documentation here.

You can also do this on Windows (with WSL) or on MacOS (with Lima) !