IT Center Blog

New software environment and operating system

March 29th, 2023 | by
Tiny programmer update the operating system of computer isolated flat illustration

Source: Freepik

Maybe you have already noticed – the changeover to a new Linux distribution on the CLAIX has been going on for some time. Now it goes into the final phase, so that the old operating system CentOS 7 will be replaced by Rocky Linux 8.7. It is compatible with Red Hat Enterprise and brings a few changes.

Full speed ahead –
parallel changeover

Going hand in hand with this change, we also prepared the shift to a new software environment based on EasyBuild and Lmod. These tools are already used by other HPC centers and are therefore widely available. We expect them to improve the user experience and the maintainability from the administrator’s perspective.

However, for you as users, both changes require that you

1) learn how to use the new module system (e.g., names of the modules changed, toolchains, etc.) and
2) recompile your software and
3) revise and possibly modify your batch scripts accordingly.

The changeover time

We are aware that you will need time for the changeover. For this reason, we are offering you parallel support for the transition period until April 30, 2023: For the old (CentOS 7) and the new (Rocky Linux 8.7) environment. During this time, computing nodes will be gradually migrated to the new environment. Consequently, wait times for jobs to run in the old environment may increase over time.

What’s the best way to proceed?

Maintenance has already taken place on March 8, migrating the nodes below to the new environment.

Since then, jobs submitted from these login nodes are automatically forwarded to compute nodes running Rocky 8.7 and the new module environment.
All batch jobs submitted from non-migrated login nodes (i.e. not in the list above) will be scheduled in the the old environment.

Want to run your workflows directly in the new environment and make changes? We have put together an example of how you can easily find software with “module spider” in the new module system on IT Center Help.

Please make sure that you use the new FastX 3 version for a graphical remote desktop session. You can find helpful tips in our documentation portal IT Center Help.

Notice from 10.05.2023:

Due to the change from CentOS 7.9 to Rocky 8.7, unexpectedly larger adjustments to the multi-factor authentication are necessary in order to make it available under Rocky 8. Because these need some more time the MFA dialog system will remain under CentOS 7.9 until this work is finished.
After the successful 2FA login on this dialog system, users can easily connect to one of the other Rocky8 dialog systems via SSH. (*)

Where can I find more information?

We have summarized an overview of the changes that the migration will bring on IT Center Help.

Detailed information about the new module system (including sample scripts for various software packages) can be found in a separate branch under “Software (Rocky 8)“.

Who can I contact if I have any questions?

Please contact for further questions or attend our HPC Consultation Hour on April 20.

Responsible for the content of this article are Marcus Wagner and Janin Vreydal.

(*) The paragraph was updated on May 10, 2023.

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