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Subject: Re: [OMPI users] explicit routing for multiple network interfaces
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-09-02 04:11:40


If you don't use btl_tcp_if_include, Open MPI should use all available
ethernet devices, and *should* (although I haven't tested this
recently) only use devices that are routable to specific peers.
Specifically, if you're on a node with eth0-3, it should use all of
them to connect to another peer that has eth0-3, but only use eth0-1
to connect to a peer that only has those 2 devices. (all of the above
assume that all your eth0's are on one subnet, all your eth1's are on
another subnet, ...etc.)

Does that work for you?

On Aug 25, 2009, at 7:14 PM, Jayanta Roy wrote:

> Hi,
>
> I am using Openmpi (version 1.2.2) for MPI data transfer using non-
> blocking MPI calls like MPI_Isend, MPI_Irecv etc. I am using "--mca
> btl_tcp_if_include eth0,eth1" to use both the eth link for data
> transfer within 48 nodes. Now I have added eth2 and eth3 links on
> the 32 compute nodes. My aim is to share the high speed data within
> 32 compute nodes through eth2 and eth3. But I can't include this as
> part of "mca" as the rest of 16 nodes do not have these additional
> interfaces. In MPI/Openmp can one specify explicit routing table
> within a set of nodes? Such that I can edit /etc/host for additional
> hostname with these new interfaces and add these hosts in the mpi
> hostfile.
>
> Regards,
> Jayanta _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users

-- 
Jeff Squyres
jsquyres_at_[hidden]