In the next months, we plan to migrate the Lichtenberg cluster's operating system to RedHat Enterprise Linux 9.

In preparation for this upgrade. just one login node (lcluster7.hrz.tu-darmstadt.de) was installed with RHEL 9.

This has now been extended to 4 login nodes (lcluster6,7,18,19) and 32 Sapphire-Rapids compute nodes (104 CPU cores, LB2A2).

For jobs, these nodes can be targeted by requesting a special partition, using the sbatch parameter „--partition=special_rhel9“. Inside job scripts, use

#SBATCH -p special_rhel9

Unfortunately, these RHEL-9 nodes cannot use the old module system any longer. Thus, a new module system based on SPACK has been installed on them.
As this module system is still under construction, we can accept user feedback.

Up to now, the available modules are mainly built using the system compiler (gcc 11.4.1).
The naming of the modules is quite different to the old system, yet not final.
While the usual LMod “module …” commands still work with the new system, you can also choose to load/activate them directly using the “spack” command.

Please test relevant software and provide us with feedback.

For a smooth and painless transition to RHEL 9, productive software should have been built and thoroughly tested under RHEL 9, before the final migration date is due.