Thanks for all your suggestions. Yes, indeed what I'm trying to do is execute a serial program. All the documentation you mention was pretty useful. I have another question, if mpirun launches several copies of the program on the different hosts, does it mean that I must have a copy of the program on all the nodes, because I'm using NFS to share the location were my program is installed and it seems to work fine when I execute mpirun with simple scripts.
Jorge.
