At present we're trying to write a program which uses mpirun to launch multiple X11 clients. If the programs are text-only, then using the following command, we can run proceses on a list of computers:mpirun -np 4 --hostfile hostlist dateHere hostlist is a file of mpi-configured computers. The computers are set up to authenticate automatically using public keys. We can also run X11 programs on the local computer only, for instance:mpirun -np 4 xclockshows four xclocks as expected. However, if we try to run X11 programs using a hostfile:mpirun -np 4 --hostfile hostlist xclockthen two xclocks launch but the remote computer reports:Error: can't open display:However, we have configured .ssh/config withForwardX11 YesAnd we can verify that the following command sequence works:ssh 10.0.0.2# connect to mpi cluster nodexclock# xclock appears on screenFurthermore, if we set a DISPLAY variable with mpirun's -x as follows:mpirun -np 4 --hostfile hostlist -x DISPLAY=10.0.0.1:0.0 xclock    Then we get another error:Error: can't open display: 10.0.0.1:0.0We tried to disable any access control with:xhost +To summarize, we'd like some help with mpirun and X11 Forwarding. We're running on Ubuntu 12.10 and openmpi 1.4.5.
mpirun with ssh and X11
ubuntu;x11;mpi
Following command seems to work wellmpirun -d -np 4 -hostfile hostlist -mca pls_rsh_agent ssh -X -n xclock