[mvapich-discuss] Can I start a job using mpirun_rsh without using ethernet?

[Jonathan Perkins]

On Wed, Jul 29, 2009 at 03:45:14PM -0600, Craig Tierney wrote:
> Jonathan Perkins wrote:
> > On Wed, Jul 29, 2009 at 02:36:41PM -0600, Craig Tierney wrote:
> >> I am trying to figure out how to launch a job with mpirun_rsh
> >> without using the ethernet.  If I specify the IBoIP addresses
> >> in my machine file, then mpispawn is launched over the IB.
> >> However, mpispawn still connects using the ethernet host names.
> > 
> > In order to do this then the hostname returned by gethostbyname would
> > have to negotiate to the IPoIB address for that host.  It sounds like
> > this is not the case in your setup.
> 
> Is it that gethostbyname needs to resolve properly, or gethostname
> does?  I wrote a small test and if you pass a IB host name, such as
> h1-ib0, that is resolves correctly.  There is a place in mpispawn that
> calls gethostname and that would resolved to the ethernet address
> given the current configuration.  I can't tell from the code path if
> that is used to communicate between hosts during the mpispawn setup or
> not.

I guess I meant the hostname passed to gethostbyname would have to
resolve to the IPoIB address for that host.  The function gethostname is
used in a couple locations to determine how things should connect to
each other when bootstrapping the mpi application.  These portions of
code will lead to traffic on whichever network the hostname returned by
gethostname is on.

> 
> Thanks,
> Craig

-- 
Jonathan Perkins
http://www.cse.ohio-state.edu/~perkinjo
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