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Subject: [OMPI users] Parallel file write in fortran (+mpi)
From: Laurence Marks (L-marks_at_[hidden])
Date: 2010-02-02 10:27:13

I have a question concerning having many processors in a mpi job all
write to the same file -- not using mpi calls but with standard
fortran I/O. I know that this can lead to consistency issues, but it
can also lead to OS issues with some flavors of nfs.

At least in fortran, there is nothing "wrong" with doing this. My
question is whether this is "One of the Seven Deadly Sins" of mpi
programming, or just frowned on. (That is, it should be OK even if it
leads to nonsense files, and not lead to OS issues.) If it is a sin, I
would appreciate a link to where this is spelt out in some "official"
document or similar.

Laurence Marks
Department of Materials Science and Engineering
MSE Rm 2036 Cook Hall
2220 N Campus Drive
Northwestern University
Evanston, IL 60208, USA
Tel: (847) 491-3996 Fax: (847) 491-7820
email: L-marks at northwestern dot edu
Chair, Commission on Electron Crystallography of IUCR
Electron crystallography is the branch of science that uses electron
scattering and imaging to study the structure of matter.