Hi, I've run into the same problem as discussed in the thread Lev Gelb: "Re: [OMPI users] Recursive use of "orterun" (Ralph H Castain)"<http://www.open-mpi.org/community/lists/users/2007/07/3655.php>
I am running a parallel python code, then from python I launch a C++ parallel program using the python os.system command, then I come back in python and keep going. With LAM/MPI there is no problem with this. But Open-mpi systematically crashes, because the python os.system command launches the C++ program with the same OMPI_* environment variables as for the Python program. As discussed in the thread, I have tried filtering the OMPI_* variables prior to launching the C++ program with an os.execvecommand, but then it fails to return the hand to python and instead simply terminates when the C++ program ends. There is a workaround ( http://thread.gmane.org/gmane.comp.clustering.open-mpi.user/986): create a *.sh file with the following lines: -------- for i in $(env | grep OMPI_MCA |sed 's/=/ /' | awk '{print $1}') do unset $i done # now the C++ call mpirun -np 2 ./MoM/communicateMeshArrays ---------- and then call the *.sh program through the python os.system command. What I would like to know is that if this "problem" will get fixed in open-MPI? Is there another way to elegantly solve this issue? Meanwhile, I will stick to the ugly *.sh hack listed above. Cheers Ides
