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Subject: Re: [OMPI users] mpi-io, fortran, going crazy... (ADENDA)
From: Pascal Deveze (Pascal.Deveze_at_[hidden])
Date: 2010-11-17 04:13:49


I think the limit for a write (and also for a read) is 2^31-1 (2G-1). In
a C program, after this value, an integer becomes negative. I suppose
this is also true in
Fortran. The solution, is to make a loop of writes (reads) of no more
than this value.

Pascal

Ricardo Reis a écrit :
> On Tue, 16 Nov 2010, Gus Correa wrote:
>
>> Ricardo Reis wrote:
>>>
>>> and sorry to be such a nuisance...
>>>
>>> but any motive for an MPI-IO "wall" between the 2.0 and 2.1 Gb?
>>>
>> Salve Ricardo Reis!
>>
>> Is this "wall" perhaps the 2GB Linux file size limit on 32-bit systems?
>
> No. This is a 64bit machine and if I write the file normaly (like just
> using Fortran open/write/close) it works without problem (I just got a
> 3.5Gb file this way).
>
> If try to use 2 processes it will also spit a 3.5 Gb file (because
> each will be writing a chunk smaller than the 2.1 Gb "limit" ?)
>
> I haven't tried to replicate the same program in C, I must admit
>
> best,
>
> Ricardo Reis
>
> 'Non Serviam'
>
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