is now available as a module on MOGON NHR.

Hello Nextflow 👋🏻

We have now deployed Nextflow 25.10.4 on MOGON NHR\KI and would like to show you how it is set up.

Two environment variables are set when the module is loaded with module load tools/Nextflow/25.10.4:

• NXF_APPTAINER_LIBRARY_DIR is set to /lustre/.nextflow-cache/librarydir and
• NXF_APPTAINER_CACHE_DIR is set to /lustre/.nextflow-cache/cachedir/${USER}.

When you run a workflow, Nextflow first checks the NXF_APPTAINER_LIBRARY_DIR location for the container file. If it is not there, Nextflow then checks the NXF_APPTAINER_CACHE_DIR location. If the container does not exist in either of these locations, Nextflow will download the container and write it to NXF_APPTAINER_CACHE_DIR. However, as this only makes the container accessible to the user who triggered the download, we regularly copy the containers of your common workflows and write them to NXF_APPTAINER_LIBRARY_DIR, so that other users do not have to download them.

We have moved the cache out of your home directory to prevent you from exceeding your quota. Naturally, you can override these two environment variables using the standard Nextflow configuration file using:

• The config file $HOME/.nextflow/config
• The config file nextflow.config in your project directory,
• The config file nextflow.config in the launch directory or
• config files specified using the -c <config-files> option.