Thomas Zeiser

Some comments by Thomas Zeiser about HPC@RRZE and other things


MpCCI auf SGI Altix

MpCCI is a library for coupling different codes (e.g. fluid mechanics and aeroaccustics) and excahnging mesh-based data between them. It is developed and sold by Fraunhofer-Institute SCAI (

MpCCI is available for several platforms and relies on MPI for communication.

The good news: MpCCI SDK is available for IA64.
The bad news: it relies on mpich

On our SGI Altix system we use PBS Professional as batch queuing system and each running job gets its own CPU-set.

When now starting a MpCCI job, a procgroup file is generated and the processes are started via ssh. And that’s exactly the problem: the sshd daemon (started by root at boot-time) runs outside the CPU-set. Consequently, all processes started via ssh are also outside the allocated cpuset … 🙂

* shared-memory mpich does not work as the shm device of mpich does not work with MPMD, i.e. a procgroup file is not suppoerted
* using SGI MPT (SGI’s own MPI) does not work as the binary-only MpCCI library relies on some mpich symbols
* starting the code with mpiexec does not work as there are some problems with accessing stdin from within the application
* …

One Response to MpCCI auf SGI Altix

  1. Irfan Ali says:

    MpCCI without MPI/MPICH
    When coupled programs are not parallel or do not use MPI/MPICH then we do’nt have the above problem.

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