It appears to be due to not being able to fully remove MPICH2 on machines that have and aged install. Then Open MPI will not overwrite the remaining crumbs and is not automagically well configured. I tested this hypothesis on an additional pair of recent/aged MPICH2 install machines. Currently reinstalling CentOS 5 on the aged MPICH2 install machine.
The problem is that the same command on the same hardware running the same code results in 2 communicating processes on the recent MPICH2 install machine that now has Open MPI on it and 2 individual processes on the aged MPICH2 install machine that now had Open MPI on it. -----Original Message----- From: users-boun...@open-mpi.org [mailto:users-boun...@open-mpi.org] On Behalf Of Ralph Castain Sent: January 5, 2011 8:09 PM To: Open MPI Users Subject: Re: [OMPI users] Duplicate independent processes I'm afraid I don't understand your example - are you saying you provide "-np 1" and get two processes instead of 1? If so, would you please provide info on the type of system where this happens? I've never seen it with mpich or ompi On Jan 5, 2011, at 4:57 PM, Kristian Medri wrote: > Any hints on what to look for to get the second machine to behave without > duplicate independent processes? > > "mpirun -np 2 ..." > > Provides as expected: > > "Using MPI version 2.1, 2 processes > .1. > .2." > > While on another similar machine: > > "Using MPI version 2.2, 1 processes > .1. > Using MPI version 2.2, 1 processes > .1. > .2. > .2." > > On both: > > /usr/lib64/openmpi/1.4-gcc/bin/mpirun --version > > Returns: > > mpirun (Open MPI) 1.4 > > I looked in the FAQ and searched the list but did not find it yet. When I > worked with MPICH2 I also had this happen from time to time. I can provide > additional information should it not be as common here. > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
