What has happened?

On December 7th, Sigma was upgrade from CentOS 7 to Rocky Linux 9.

The changes were kept to a minimum. You can still use SSH or Thinlinc to log in, you can still submit your jobs to Slurm, etc.

Storage (/proj, /home) are not affected (i.e no need to move your data).

What will happen

• During early 2024 (February to April): a 1-2 day stop to upgrade the cluster system servers (job scheduler, etc.) and do some other required maintenance. Date not decided yet.

What do I need to do?

To continue using Sigma without interruption after the upgrade, we recommend that you:

1. Read the documentation available on this page and see if there is anything relevant to your applications.
2. Login to Sigma and try to get your jobs running using information found on this page. If you run into problems, contact NSC Support.

If you have any questions regarding the upgrade that you cannot find the answer to here, contact NSC Support.

Applications provided by NSC

Most applications provided by NSC will continue to work. Just as before, the same applications will be available on both Tetralith and Sigma.

Additional applications and versions can be added, but only if requested via NSC Support.

If you don’t find your application/version in the output from module avail (on upgraded nodes) and it’s not mentioned on this page already, please contact NSC Support and ask about it.

Some of the NSC-provided applications will run natively in the new operating system, some will have been recompiled and others will be run in a CentOS 7 container using Apptainer. We aim to make all this as transparent to the user as possible, but minor adjustments to job scripts may be needed (and documented on this page).

Additional information might be available on the Tetralith upgrade page.

Applications you or your project have installed yourself

If you or someone in your project has built or installed your own application you will need to choose a suitable way to run the application in the new environment. There are several ways to do this (recompile, run as-is, run in a container). Which one to use depends on the application. NSC Support can assist you with this. Documentation will also be available on this page later.

Additional information might be available on the Tetralith upgrade page.

Application performance

NSC has run applications on the upgraded part of Tetralith (both recompiled, run as-is, and run through a CentOS 7 container) and not seen any significant negative performance impact. In fact, some applications are even running faster.

If you see a significant performance loss in Sigma after the upgrade or in the the upgraded part Tetralith, please let NSC Support know as soon as possible.

If you cannot get your application working on Rocky 9

If you cannot get your application working on Rocky 9, contact NSC Support.

Why have we done this?

The previous operating system CentOS 7 (which is based on RedHat Enterprise Linux 7) will not receive any security updates after 2024-06-30.

As Sigma is planned to continue operating longer than this, possibly until late 2025, we needed to upgrade the operating system.