Use the "--exclusive" option to always get whole node allocations:
$ sbatch --exclusive -N 3 my.bash
I would use the "--ntasks-per-node=1" option to control the task count
per node:
srun --ntasks-per-node=1 my.app
I would also recommend this document:
http://slurm.schedmd.com/mc_support.html
Quoting gareth.willi...@csiro.au:
We have a cluster with dual socket nodes with 10-core cpus (ht off)
and we share nodes with SelectType=select/cons_res. Before (or
after) running an MPI task, I'd like to run some pre (and post)
processing tasks, one per node but am having trouble finding
documentation for how to do this. I was expecting to submit a jobs
with sbatch with --nodes=N --tasks-per-node=20 where N is an integer
to get multiple whole nodes then run srun --tasks-per-node=1 for the
per node tasks but this does not work (I get one task for each core).
I'd also like any solution to work with hybrid mpi/openmp with one
openmp task per node or per socket.
Thanks,
Gareth
--
Morris "Moe" Jette
CTO, SchedMD LLC
Commercial Slurm Development and Support
