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.


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


 Ricardo Reis

 'Non Serviam'

 PhD candidate @ Lasef
 Computational Fluid Dynamics, High Performance Computing, Turbulence

 Cultural Instigator @ Rádio Zero

 Keep them Flying! Ajude a/help Aero Fénix!



 contacts:  gtalk: kyriusan@gmail.com  skype: kyriusan

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