[mpich-discuss] forrtl errors

[Gus Correa]

Hi Christopher and list

A number of different problems can generate I/O errors in a parallel 
environment.
Some that I came across with (there are certainly more):

1) Permissions on the target directory. (Can you read and write there?)
2) If you are running on separate hosts (a cluster or a "NOW"),
are you doing I?O to local disks/filesystems, or to a NFS mounted directory?
2.A) If local disks, are the presumed directories already created there, 
and with the right permissions?
2.B) If NFS, is the export/mount mechanism operating properly?
3)  On which directory do your processes start in each execution host?
The same as in the host where you launch the mpiexec command or on a 
different directory? 
(See mpiexec -wdir option, assuming you are using the mpiexec that comes 
with MPICH2. 
There are other mpiexec commands, though.)
4) Code (Fortran code, I presume) that makes wrong assumptions about 
file status,.
e.g. "open(fin,file='myfile',status=old)" but 'myfile' doesn't exist yet.

Witting a very simple MPI test program that where each process 
opens/creates, writes, and closes,
a different file may help you sort this out.

Also, I wonder if your precompiled commercial applications are using the 
same MPICH2 that
you configured, or some other MPI version.

I hope this helps,
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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Christopher Tanner wrote:

> Hi All -
>
> I am receiving the same errors in multiple applications when I try to  
> run them over MPICH2. They all read:
>
> forrtl: Input/output error
> forrtl: No such file or directory
> forrtl: severe ...
>
> This doesn't happen when I try to run any tests (i.e. mpiexec ...  
> hostname), only whenever I run the applications. Additionally, it  
> happens with pre-compiled (i.e. commercial applications) applications  
> as well as applications compiled on the machine (i.e. open-source  
> applications). At first I thought it was something to do with the  
> application, now I'm starting to think I've done something wrong with  
> MPICH2. Below is the configure command I used:
>
> ./configure --prefix=/usr/local/mpi/mpich2 --enable-f77 --enable-f90 
> -- enable-cxx --enable-sharedlibs=gcc --enable-fast=defopt CC=icc 
> CFLAGS=- m64 CXX=icpc CXXFLAGS=-m64 F77=ifort FFLAGS=-m64 F90=ifort 
> F90FLAGS=-m64
>
> Anyone have any clues? Thanks!
>
> -------------------------------------------
> Chris Tanner
> Space Systems Design Lab
> Georgia Institute of Technology
> christopher.tanner at gatech.edu
> -------------------------------------------
>
>