Newsgroups: comp.parallel.mpi
From: Nick Nevin <nevin@osc.edu>
Reply-To: nevin@osc.edu
Subject: Re: LAM/MPI 6.0 question about mpirun
Organization: Ohio Supercomputer Center
Date: 07 Oct 1996 09:14:18 -0400
Message-ID: <vn2u3s6kjbp.fsf@bedrock.osc.edu>


>>>>> " " == Michael D Beynon <beynon@cs.umd.edu> writes:

     > I have been developing an mpi application using LAM/MPI 6.0.
     > For debugging, I have been not using mpirun to start my job.
     > Instead, I can open an xterm to each node in my bhost.def file
     > and then manually run each program on each of the nodes from
     > the xterm.  There is a special case in LAM that will cause
     > this job to start as if I had used mpirun N.

     > Now the question ...

     > When I now try to use mpirun, it starts to run, and then
     > fails with the message
     > 	MPI_Recv: invalid rank (rank 2, comm 0)

     > Is there any real difference when using mpirun?

Process startup is different but everything should appear the same to
the application code.  What does your mpirun command line look like?  It
appears you might not be running as many processes as expected and
process rank two is trying to receive from a non-existent process.
Does the application use MPIL_Spawn()?

---nick.

-=-
Nick Nevin				nevin@osc.edu
Ohio Supercomputer Center		http://www.osc.edu/lam.html

