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Karolina

EESSI, the base of the EFP Federated Software Catalog, is available system-wide on Karolina via a native CernVM-FS deployment since early 2025.

Synchronisation

Karolina is synchronised daily with the public EESSI infrastructure. This means that once new software has been integrated into EESSI, the maximum wait time for it to appear on the system is under an hour.

Access

Standard access instructions apply.

Usage

EESSI is available by default on both login and compute nodes but requires initialisation. See the initialisation instructions for the Federated Software Catalog and then continue with loading your required software.

Known problems and limitations

  • Karolina tracks module loads via the module tool Lmod. When you initialise EESSI you change the version of Lmod being used, this leads to harmless warnings such as 
    sh: -c: line 1: syntax error near unexpected token `('
sh: -c: line 1: `/bin/logger -t lmod -p user.notice -- sampleuser Hacn49 CKarolina IDXXXXXXX, cmd=cmdfuncs.lua:(Restore)       restore, args='
  • GPU drivers for EESSI are currently not available, they require site configuration and will be added soon.

System-specific best practices

Multi-node jobs

We provide an example of running a latency test between nodes from the OSU Micro-Benchmarks suite. This is done on 2 nodes, checking the node-to-node latency: 

# Allocate resources for the test
# (2 nodes, 1 task per node)
salloc --time=00:30:00 --account="<SLURM_ACCOUNT>" --partition=qcpu --nodes 2 --ntasks-per-node 1 --cpus-per-task 1
# Configure the EESSI environment and load the modules we need for our test
source /cvmfs/software.eessi.io/versions/2025.06/init/lmod/bash
module load OSU-Micro-Benchmarks/7.5-gompi-2025a
# Check we have two different nodes
srun --mpi=pmix -n 2 hostname
# Launch our latency test
srun --mpi=pmix -n 2 osu_latency

Note that we must include --mpi=pmix above, or equivalently set the $SLURM_MPI_TYPE environment variable to pmix, to tell Slurm how to launch our MPI processes.

Getting help with using FSC on Karolina

If you need help with using EESSI on Karolina, please contact EFP Helpdesk.

References