Paul, which OpenMPI version are you using ?
thanks for providing a simple reproducer, that will make things much easier from now. (and at first glance, that might not be a very tricky bug) Cheers, Gilles On Wednesday, December 9, 2015, Paul Kapinos <kapi...@itc.rwth-aachen.de> wrote: > Dear Open MPI developers, > did OMPIO (1) reached 'usable-stable' state? > > As we reported in (2) we had some trouble in building Open MPI with ROMIO, > which fact was hidden by OMPIO implementation stepping into the MPI_IO > breach. The fact 'ROMIO isn't AVBL' was detected after users complained > 'MPI_IO don't work as expected with version XYZ of OpenMPI' and further > investigations. > > Take a look at the attached example. It deliver different result in case > of using ROMIO and OMPIO even with 1 MPI rank on local hard disk, cf. (3). > We've seen more examples of divergent behaviour but this one is quite handy. > > Is that a bug in OMPIO or did we miss something? > > Best > Paul Kapinos > > > 1) http://www.open-mpi.org/faq/?category=ompio > > 2) http://www.open-mpi.org/community/lists/devel/2015/12/18405.php > > 3) (ROMIO is default; on local hard drive at node 'cluster') > $ ompi_info | grep romio > MCA io: romio (MCA v2.0.0, API v2.0.0, Component v1.10.1) > $ ompi_info | grep ompio > MCA io: ompio (MCA v2.0.0, API v2.0.0, Component v1.10.1) > $ mpif90 main.f90 > > $ echo hello1234 > out.txt; $MPIEXEC -np 1 -H cluster ./a.out; > fileOffset, fileSize 10 10 > fileOffset, fileSize 26 26 > ierr 0 > MPI_MODE_WRONLY, MPI_MODE_APPEND 4 128 > > $ export OMPI_MCA_io=ompio > $ echo hello1234 > out.txt; $MPIEXEC -np 1 -H cluster ./a.out; > fileOffset, fileSize 0 10 > fileOffset, fileSize 0 16 > ierr 0 > MPI_MODE_WRONLY, MPI_MODE_APPEND 4 128 > > > -- > Dipl.-Inform. Paul Kapinos - High Performance Computing, > RWTH Aachen University, IT Center > Seffenter Weg 23, D 52074 Aachen (Germany) > Tel: +49 241/80-24915 >
