Am 17.06.2014 um 14:53 schrieb firstname.lastname@example.org:
> I should have written that...
> mpirun -np n --hostfile host.cfg
> mpi@Ries slots=n_1 max_slots=n_1
> mpi@Euler slots=n_2 max_slots=n_2
Although it's defined to use characters in a case insensitive manner in hostnames, my experience is that not all calls are mapping it in a proper way. To avoid any confusion because of this, it's best to have them all in lowercase. I don't know whether this is related to your observation.