Disable UCX and libfabric vy default for OpenFOAM example

Author: ocaisa

OpenFOAM/run.sh

@@ -2,7 +2,15 @@
 
 if [[ $EESSI_CVMFS_REPO == "/cvmfs/software.eessi.io" ]] && [[ $EESSI_VERSION == "2023.06" ]]; then
     echo "Running demo for OpenFOAM v11 ..."
-    export OMPI_MCA_rmaps_base_oversubscribe=true
+    
+    # Allow oversubscription in case we don't have enough available cores
+    export OMPI_MCA_rmaps_base_oversubscribe=${OMPI_MCA_rmaps_base_oversubscribe:-"true"}
+    # By default disable UCX and libfabric since we typically run these examples on demo nodes without fast interconnect
+    export OMPI_MCA_osc=${OMPI_MCA_osc:-"^ucx"}
+    export OMPI_MCA_btl=${OMPI_MCA_btl:-"^openib,ofi"}
+    export OMPI_MCA_pml=${OMPI_MCA_pml:-"^ucx"}
+    export OMPI_MCA_mtl=${OMPI_MCA_mtl:-"^ofi"}
+
     ./bike_OpenFOAM_v11.sh
 else 
     echo "Don't know which OpenFOAM module to load for ${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}" >&2