[slurm-users] ntasks and cpus-per-task

[Miguel Gutiérrez Páez]

Hi all,

I'm quite noob in slurm and I'm still learning how slurm works.
There are some concepts that get me confused. For example, the difference
between ntasks and cpus-per-task in sbatch and/or srun. I've noticed that
cpus-per-task (and ntasks=1) allocates cpus (cores) within the same compute
node. A value of cpus-per-task higher than the max number of cores of any
node, will fail, since it seems that tries to allocate cores within the
same node. With ntasks is different. If I set a ntasks value higher than
the number of cores of a node, slurm allocates cores within several nodes,
in a linear mode.
So, should I understand cpus-per-task as the number of cpus/cores/thread I
want to use? What's the real meaning of ntasks? Has cpus-per-task and
ntasks the same meaning in sbatch and srun?

Best regards.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.schedmd.com/pipermail/slurm-users/attachments/20180222/444a51a7/attachment.html>