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Working on a shared cluster
2025.11.04· 1 min

Login nodes are not compute

Working on a shared cluster........................................................................................................................................................................................................Start
Login nodes are not compute........................................................................................................................................................................................................1
Environment modules are a contract........................................................................................................................................................................................................2
Anatomy of a Slurm job that actually finishes........................................................................................................................................................................................................3
From login node to first GPU kernel........................................................................................................................................................................................................4
A login node is a waiting room with a compiler. It is not a 128-core workstation that happens to have SSH.

What belongs on login#

  • Editing job scripts
  • sbatch, squeue, module spider
  • A tiny configure test, if the site asks for it

What does not#

  • make -j on a full application
  • Python that reads the whole mesh into RAM
  • mpirun "just to see"

Move the work#

salloc for an interactive compile. A short serial job for a configure. Scratch, not $HOME, for anything that will be written again in ten minutes.
If you need a rule you can shout across the office: if it would make your laptop fan spin, it does not belong on login.
The gif of that mistake lives in What a note can carry.
Working on a shared cluster........................................................................................................................................................................................................Previous
Environment modules are a contract........................................................................................................................................................................................................Next
#etiquette#batch
Environment modules are a contract........................................................................................................................................................................................................2024.09.18
Anatomy of a Slurm job that actually finishes........................................................................................................................................................................................................2026.08.11
From login node to first GPU kernel........................................................................................................................................................................................................2026.06.16
Why site-independent HPC notes still matter........................................................................................................................................................................................................2026.08.24
What a note can carry........................................................................................................................................................................................................2026.09.02
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