Some examples of stupid things to do on LUMI

• Poll the scheduler at high frequency.

  Even squeue is an expensive command for Slurm, and when it is receiving too many such requests, scheduling jobs may actually be halted. Slurm runs on a single server, is multi-threaded but with large critical sections, so the amount of parallelism in scheduling is limited.

  Example of something that should absolutely not be done:

  watch squeue --me
  

  which would poll the scheduler every 2 seconds. Don't poll more frequently than once a minute or even less.

• Use a different scp command for each file to transfer and use this to transfer 50000 files, bombarding the login nodes with ssh login requests. It will make you look very suspicious and is not an efficient use of resources.