We will be upgrading the operating system on the Fritz cluster from AlmaLinux 8 to AlmaLinux 9. That means you will have to adapt your jobs. Most development and application software provided by us as “modules” is updated to current versions, old versions will usually no longer be available unless there is a good reason for that. If you compiled software yourself, you will need to recompile, as the version of libraries provided by the OS or our modules will change significantly.
The update will happen gradually over the course of the next month, that means the number of nodes running AlmaLinux 9 will gradually increase, while the number of nodes still running AlmaLinux 8 will be reduced further and further until there are none left. We recommend to switch to the AlmaLinux 9 nodes as soon as possible.
Currently, connecting to fritz.nhr.fau.de will take you to one of the AlmaLinux 9 login nodes. There are no more AlmaLinux 8 login nodes, and the temporary DNS entry fritz9.nhr.fau.de that permitted you to test the new AlmaLinux 9 login nodes no longer exists.
Timeline
The timeline is currently planned as follows:
- 2026-06-08:
fritz9.nhr.fau.deis available as AlmaLinux 9 login node for testing. - 2026-07-06:
fritz.nhr.fau.denow points to the AlmaLinux 9 login nodes, i.e. AlmaLinux 9 becomes the default. AlmaLinux 8 login nodes turned off. AlmaLinux 8 jobs already queued will still be processed, but slower and slower. - mid of July: no more AlmaLinux 8 nodes are remaining, with the exception of the visualization node
fviz1. - mid of July: visualization node
fviz1gets reinstalled with AlmaLinux 9. This is expected to take a while due to the complexity of its software-stack, so it will not available for a few days.
We will keep this post updated.
Using the AlmaLinux9 environment
As of Tuesday, July 07, AlmaLinux 9 has become the default. All frontend have the new AlmaLinux 9 environment.
For a limited time, you will still be able to submit jobs to run under AlmaLinux 8. For that, you need to add -C el8 or --constraint=el8 to your Slurm commandline. (If you need additional constraints like e.g. hwperf, you need to concatenate them with an ampersand, i.e. -C el9&hwperf.) Note that the number of nodes available under AlmaLinux 8 will be reduced further and further over the next two weeks, until none are remaining. You should switch your jobs to AlmaLinux 9 as soon as possible.
Log of relevant changes
2026-06-22: Timeline pushed back by two weeks.
2026-07-07: AlmaLinux 9 is now the default. All login nodes are running AlmaLinux 9.