I'm using ClusterTools 8.2.1 on Solaris 10 and according to the HPC docs, "Open MPI includes a commented default hostfile at /opt/SUNWhpc/HPC8.2/etc/openmpi-default-hostfile. Unless you specify a different hostfile at a different location, this is the hostfile that OpenMPI uses."
I have added my list of hosts to that file. If I don't specify a hostfile in the mpirun command, it doesn't use any of the hosts in the file, it just runs everything on the node that I run the command on. However, if I implicitly call the hostfile in the mpirun command with -hostfile /opt/SUNWhpc/HPC8.2.1/etc/openmpi-default-hostfile, then it works as it should. So, I have come to the conclusion that mpirun is not reading my default file for some reason. Is there a way to figure out why? Benj