I have recently installed OpenMPI 1.1.2 on a OpenSSI cluster running Fedora core 3. I tested a simple hello world mpi program (attached) and it runs ok as root. However, if I run the same program under normal user, it gives the following error:

[eddie@oceanus:~/home2/mpi_tut]$ mpirun -np 2 tut01
[oceanus:125089] mca_common_sm_mmap_init: ftruncate failed with errno=13
[oceanus:125089] mca_mpool_sm_init: unable to create shared memory mapping ( /tmp/openmpi-sessions-eddie@localhost_0/default-universe/1/shared_mem_pool.localhost)
--------------------------------------------------------------------------
It looks like MPI_INIT failed for some reason; your parallel process is
likely to abort. There are many reasons that a parallel process can
fail during MPI_INIT; some of which are due to configuration or environment
problems. This failure appears to be an internal failure; here's some
additional information (which may only be relevant to an Open MPI
developer):

PML add procs failed
--> Returned "Out of resource" (-2) instead of "Success" (0)
--------------------------------------------------------------------------
*** An error occurred in MPI_Init
*** before MPI was initialized
*** MPI_ERRORS_ARE_FATAL (goodbye)
[eddie@oceanus:~/home2/mpi_tut]$

Am I need to give certain permission to the user in order to oversubscribe processes?

Thanks in advance,

Eddie.