[mpich-discuss] forrtl errors

[Christopher Tanner]

Gus / All -

I've NFS mounted the /home directory on all nodes. To ensure that the  
permissions are correct and the NFS export mechanism is correct, I  
ssh'ed to each node and made sure I could read and write files to the / 
home/<user> directory. Is this sufficient to ensure that mpiexec can  
read and read to the home directory?

I'm launching the process from the /home/<user> directory, where the  
data files to be read/wrote are. The executable is in the NFS exported  
directory /usr/local/bin.

Regarding the code itself making I/O errors, this is what I assumed  
initially. Since it occurred on two different applications, I'm  
assuming it's the MPI and not the application, but I could be wrong.

Does anything here stand out as bad?

I emailed out the output from my configure command -- hopefully this  
may shed some light on the issue.

-------------------------------------------
Chris Tanner
Space Systems Design Lab
Georgia Institute of Technology
christopher.tanner at gatech.edu
-------------------------------------------



On Oct 7, 2008, at 3:37 PM, Gus Correa wrote:

> 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
>
> -- 
> ---------------------------------------------------------------------
> 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
> ---------------------------------------------------------------------
>
>
> 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
>> -------------------------------------------
>>
>>
>