Re: Spreading parallel across nodes on HPC system

[Ken Mankoff]

On 2022-11-11 at 08:37 +01, Rob Sargent <robjsargent@gmail.com> wrote:
> How do you mix slurm and parallel hostfile?

I have a script S that launches parallel with 30 tasks via "::: $(seq 30)"

I start S with "sbatch" and --ntasks=31. One for S itself, 30 for the parallel 
processes.

When slurm gives me 1 node with 31 cores (or cpu?) things run fast. But 
sometimes I get 31 nodes with 1 core each, and then parallel only sees "1" and 
it runs things sequentially and 30 (or 29?) nodes are not used.

I realize from above that if parallel only sees 1 core in this case, then I've 
answered my last question - parallel sees what I'm allocated, not what is 
physically available. Therefore, I think just passing "--slf nodelist" should 
solve everything.

  -k.