[Users] Cactus Core Usage on HPC Cluster

Hi All,

I'm trying to get the Einstein Toolkit installed on an HPC cluster running SLES. The trouble is that Cactus tries to use all the available processors even when I specify a smaller number (by setting ppn in my PBS script).

As a test, I tried running the compilation with a parameter file that required about 5 GB of RAM. In my PBS script, I set nodes=1 and ppn=3, and then ran using openmpi-1.10.1:

mpirun -hostfile $PBS_NODEFILE <ET exe> <parameter file>

This resulted in the simulation running on all 24 available processors, even though I'd only requested 3. Since PBS and MPI are integrated, I was told that using -np with mpirun wouldn't help.

Does anyone know how to address this issue?

Thanks,

Gwyneth