Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

From: Marcin Skoczylas (Marcin.Skoczylas_at_[hidden])
Date: 2007-10-23 06:06:52

Michael wrote:
> The primary difference seems to be that you have all communication
> going over a single interface.

Yes. It's clearly stated in the OpenMPI FAQ that such configuration is
not supported:

These rules do /not/ cover the following cases:

    * Running an MPI job that spans a bunch of private networks with
      narrowly-scoped netmasks, such as nodes that have IP addresses and with netmasks of
      (i.e., the network fabric makes these two nodes be routable to
      each other, even though the netmask implies that they are on
      different subnets).

This is exactly our case. Anyway, after a discussion with our
administrators, we decided to use a walkaround, I run my program only on
worker nodes from network, and I got a direct route to
these machines from my computer, outside the cluster's private network.
So in this configuration, one of worker nodes became a head, and
cluster's head is not being used at all.
That solved problem.

Thank you for your support!

regards, Marcin Skoczylas