I am in the process of moving a ROCKS cluster that uses Red Hat 5.4 to a new Cluster using the same hardware, but Red Hat 6,6, and Rocks 6.1.1. I am slowly moving each node to the new cluster. I have very old Infiniband HBAs connected to a switch. That switch can see the nodes that remain in the old cluster, and the new ones that have been moved. I downloaded and installed MVAPICH2 from OSU and its benchmarking. I had a user compile his software with OpenMPI and the MVAPICH2. I looked at the libraries being called by his very of OpenMPI and didn't see and Infiniband libraries being used. They were clearly used in MVAPICH2, yet the OpenMPI compile ran faster.

We have another small cluster using IB. This is my first use. Should an IP address be assigned to each IB HBA? I am not sure than I have thing installed correctly. I tried downloading and installed the Melanox software and it could upgrade the firmware and just puked. At least Red Hat's support 'seems' to work. If I selected nodes to process the data that doesn't have IB, it blows up. If I stick to nodes with IB HBAs in them, the program runs, but I am convinced the first version compiled with OpenMPI is using ethernet and not Infiniband, but runs faster.