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Subject: Re: [OMPI users] Test works with 3 computers, but not 4?
From: David Doria (daviddoria+openmpi_at_[hidden])
Date: 2009-07-29 16:06:58


On Wed, Jul 29, 2009 at 3:42 PM, Ralph Castain <rhc_at_[hidden]> wrote:

> It sounds like perhaps IOF messages aren't getting relayed along the
> daemons. Note that the daemon on each node does have to be able to send TCP
> messages to all other nodes, not just mpirun.
>
> Couple of things you can do to check:
>
> 1. -mca routed direct - this will send all messages direct instead of
> across the daemons
>
> 2. --leave-session-attached - will allow you to see any errors reported by
> the daemons, including those from attempting to relay messages
>
> Ralph
>
>
Ralph, thanks for the quick response.

With
-mca routed direct
it works correctly.

With this:
mpirun -H 10.1.2.126,10.1.2.122,10.1.2.123,10.1.2.125
--leave-session-attached -np 4 /home/doriad/MPITest/hello-mpi

I still get no output nor errors from the daemons.

Is there a downside to using 'mca routed direct'? Or should I fix whatever
is causing this daemon issue? You have any other tests for me to try to see
what's wrong?

Thanks,

David