Cluster Computing Infrastructure


Victor Penso

Matteo Dessalvi


April 18, 2024


This web-site describes the High-Performance Computing (HPC) infrastructure build by the GSI IT Department. The HPC facility is build for physics simulation and experiment data analysis. The infrastructure is available to all scientists associated with GSI and/or FAIR experiments.

Figure 1: Green Cube building at GSI Darmstadt

The Virgo cluster has replaced its predecessor Kronos after being in production from 2015 until end of 2020. The system was made available to selected users as pre-production in June 2020 and entered production in August 2020. The entire cluster infrastructure is located in the Green Cube compute center (see Figure 1) at GSI Darmstadt. All applications on Virgo run in Linux containers and allow for a complete separation of host platform from user workload. This enables the continues upgrade of the cluster without interference for users. Following table lists upgrades to Virgo since it came into production status:

Date Version Base OS Slurm Lustre CVMFS Container Engine CUDA ROCm
2020/03 1.0 CentOS 7.7 18.04 2.12 2.6 Singularity 3.4
2020/07 1.1 CentOS 7.8 18.04 2.12 2.7 Singularity 3.6
2021/02 1.2 CentOS 7.9 18.04 2.12 2.8 Singularity 3.7 11 4.1
2022/02 2.0 RockyLinux 8.6 21.08 2.12 2.9 Apptainer 1.1 11.4 5.3
2023/10 2.1 RockyLinux 8.8 21.08 2.15 2.11 Appatiner 1.2 11.4 5.3
2024/03 3.0 RockyLinux 8.9 23.11 2.15 2.11 Apptainer 1.3 tbd 6.0

Virgo provides Virtual Application environments (VAEs) based on containers. VAEs enable multiple different user environments on a single host platform. The cluster computing group supports a selection of VAEs for common use-cases. All users can build and run their own custom containers as well.

The capabilities of the workload management system have been adapted to allow flexible partitioning of resources. This is particularly useful in order to dynamically orchestrate groups of compute nodes upon requests for online-computing by different scientific experiments. The following document introduces the reader to the software and hardware platform composing the Virgo cluster infrastructure, and illustrates very basic examples how to use this resource for scientific computing.