Access

How do I apply for cluster access?

We describe the process here.

Do I have to pay money to use the cluster?

No, all members of the University of Siegen (students and staff) can use the cluster without having to pay any money. You may have to pay license fees for the use of certain software, e.g. Abaqus
in which case you will be shown a warning when loading the module.
a warning will be displayed.

My chair is part of an industrial cooperation, can I use your systems?

No, unfortunately industry-funded projects are not allowed to use our computing resources.

Does ZIMT have GPU nodes?

Yes, the OMNI cluster has 10 nodes with a total of 24 nVidia Tesla V100 GPUs, more information here.

When will the new cluster be available?

The OMNI cluster was opened for general operation on March 8, 2021.

Invoices

Why do I have to create my own job scripts and learn SLURM options, can't this be automated?

Even though you could simplify or automate the process of writing job scripts and setting jobs even more, we have decided not to support this in most cases. This is because you share the limited resources of the cluster with all other users and we want you to gain a basic understanding and think about your resource usage.

I have an urgent deadline, can you raise my priority?

No. The capacity of the cluster is limited, and the scheduler SLURM schedules jobs according to a fair-share/backfilling algorithm that ensures the least waiting time for everyone. It is our stated policy not to interfere with this system.

User X comes before me, even though my job is longer in the queue!

The prioritization algorithm used by SLURM has four main criteria:

• Fair share: if a user consumes a lot of resources (i.e. a lot of CPU time) in a short time, the priority for subsequent jobs drops. This criterion is by far the most heavily weighted.
• Age: the longer a job is in the queue, the higher the priority
• Job size: large jobs are slightly preferred to compensate for the longer waiting time
• Backfilling: after the jobs have been sorted according to the above three criteria, SLURM fills any gaps with smaller jobs, which are therefore queued earlier.

You can display the priorities using the sprio command.

Can I reserve computing time?

Not for regular computing jobs. In exceptional cases, we set up reservations for certain courses so that participants can run their jobs directly during the course. Please contactus
us if you are interested.

Help, my job has been canceled!

This can have many different causes. First of all, you should check the SLURM log file for error messages (especially at the end of the log file). If your job is aborted with the message "not enough memory", you may have requested too little RAM in the SLURM settings (option --mem), more on this here.

If you cannot recognize the error, send the log file and the job script with a description of the problem to hpc-support@uni-siegen.de.

Software

What software is installed on the cluster?

On our start page you will find an overview of the installed software and available compilers and interpreters. If you already have cluster access, you can use module avail to display the installed modules (note: it is possible that software may not be used by all members of the university or may only be used for a fee, in which case you will receive a warning when loading the module).

Can you please install software X?

We decide on a case-by-case basis whether to install something. It is best to come to our office hours
or contact us by email.

Can you please update software Y?

We decide on a case-by-case basis whether to update software. In order to keep the maintenance effort manageable and to ensure compatibility and security, we only install software from certain sources (such as the operating system manufacturer's software repository) where the latest versions are not always available.

Files

Help, I have accidentally deleted files from my home directory!

Daily snapshots of your home directory are created automatically. If you don't wait too long (maximum 30 days), you can restore the files yourself. How you can do this is described here
described here.

Help, my workspace has expired!

In the first 10 days after your workspace expires, you can restore it yourself; how to do this is described here
described here.