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Subject: Re: [OMPI users] Parallel I/O with MPI-1
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2008-07-23 08:27:32


On Jul 23, 2008, at 8:24 AM, Gabriele Fatigati wrote:

> >You could always effect your own parallel IO (e.g., use MPI sends
> and receives to coordinate parallel reads and writes), but >why?
> It's already done in the MPI-IO implementation.
>
> Just a moment: you're saying that i can do fwrite without any lock?
> OpenMPI does this?

No. I'm saying that you can either effect your own locks with MPI
sends and receives (i.e., more-or-less equivalents of flock, because,
IIRC, flock on NFS is not reliable -- but I'm not an expert in this
area, so you might want to double check that), or you could just use
MPI-IO.

> And, what is ROMIO? Where can i find any informations?

Sorry, ROMIO is the implementation of the MPI-2 IO chapter that Open
MPI uses. ROMIO is embedded in Open MPI and is built by default. So
you can use all the MPI-2 IO stuff if you're using Open MPI.

-- 
Jeff Squyres
Cisco Systems