I now solved the "ssh" part of my Problem The XServer is being started with the nolisten option (thanks Allen). In Fedora (Gnome) this can easily be changed by choosing the the "Login Screen" tool from the System|Administration Menu. There, under the tab "Security", remove the checkmark from "Deny TCP connections from xserver" Of course, this needs root access - fortunately, i am the boss of my computer ;) Additionally, at least the port 6000 should be open.
This leaves me with my second problem $mpirun -np 5 -hostfile testhosts -x DISPLAY=plankton:0.0 xterm -hold -e ./MPITest Opens 2 xterms from nano (remote) and 3 xterms from plankton(local). The local screens display the message: ./MPITest: error while loading shared libraries: libmpi_cxx.so.0: cannot open shared object file: No such file or directory Which is unbelievably strange, since for all xterms (local & remote) the output of $mpirun -np 5 -hostfile testhosts -x DISPLAY=plankton:0.0 xterm -hold -e printenv contains the PATH variable containing the path to openmpi/bin and the LD_LIBRARY_PATH containing the path to openmpi/lib Doing $mpirun -np 5 -hostfile testhosts -x DISPLAY=plankton:0.0 xterm -hold -e locate libmpi_cxx returns on all xterms (local & remote) /opt/openmpi/lib/libmpi_cxx.la /opt/openmpi/lib/libmpi_cxx.so /opt/openmpi/lib/libmpi_cxx.so.0 /opt/openmpi/lib/libmpi_cxx.so.0.0.0 On the other hand, the application has no problem when being called without xterms: $mpirun -np 5 -hostfile testhosts ./MPITest Does anybody have an idea why that should happen? Thanks Jody
