[Beowulf] Can one Infiniband net support MPI and a parallel file system?

[Gus Correa]

Hello Beowulf fans

Is anybody using Infiniband to provide both
MPI connection and parallel file system services on a Beowulf cluster?

I thought to have a storage node that would
serve a parallel file system to the beowulf nodes over IB
(something like a NFS on steroids).
The same IB net would also work as the MPI interconnect.

Is this design possible?

On a small cluster, does it require two separate IB physical networks 
(cards and switch),
or can it be done with a single IB card per node and one switch?

Is this design efficient?

Are there other practical and  cost effective alternatives to this idea?

Would this type of design work with GigE instead of IB?

I confess I know nothing about parallel file systems and IB.
So, please forgive me if my questions are nonsense.

I also appreciate any links to readings that would mitigate my ignorance
on these subjects.

Thank you,
Gus Correa

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Gustavo J. Ponce Correa, PhD - Email: gus at ldeo.columbia.edu
Lamont-Doherty Earth Observatory - Columbia University
P.O. Box 1000 [61 Route 9W] - Palisades, NY, 10964-8000 - USA
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