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Interactive CPU nodes

Aim: Describe how to access and use the interactive CPU nodes on the Stoomboot cluster.

Target audience: Users of the Stoomboot cluster.


Nikhef's interactive Stoomboot nodes can be a great resource when starting to work on your analysis, building scripts and compiling software.

These machines are intended for:


Access and Use

The three interactive nodes can be accessed via ssh:

Node name CPU model Total RAM Operating System AMD EPYC 7551P 32-Core Processor 265 GB CentOS 7 AMD EPYC 7551P 32-Core Processor 265 GB CentOS 7 AMD EPYC 7702P 64-Core Processor 512 GB Alma Linux 9

If trying to access the nodes from home via ssh, use EduVPN with institute access and or login through

You are free to share these powerful nodes as long as you play fair with others:

Do not run memory and/or CPU intensive work for an extended period of time!

So it is ok to:

  • Run an program that uses a lot of memory for a couple of minutes
  • Run a program that uses many CPU cores for a couple of minutes
  • Run a background job that does not use either for several hours

It is not ok to:

  • Start a process that forks as many threads as there are cores (there is plenty of software around that behaves like this!) and leave it running overnight
  • Start an program that slowly eats up all the memory
  • Start a background task that runs forever and go on vacation

The interactive nodes are well suited for prototyping your analysis programs; when you are ready to do production runs, scale up by using the batch system.

If, for some reason, you have to run a long CPU-intensive job on the interactive nodes (i.e., you cannot run it on the batch system), please be friendly to your fellow users of the system and run your jobs with low CPU priority using the nice command:

nice -20 <your script or program and its arguments>

This way, your program gets a lower priority than other programs, which means it will take a bit longer to complete for you, but makes the system more responsive for other users.