mpiexec fails as MPI init aborts

I am trying to install MPICH 2 on a 64-bit machine running on Ubuntu 11.04 (Natty Narwhal). I used

sudo apt-get install mpich2

First I was surprised to see that mpd was not installed. On looking up on Google, I saw that Hydra is the new default package manager. So I tried to run my MPI code. I got the following error.

> -------------------------------------------------------------------------------------------
> [ip-10-99-75-58:02212] [[INVALID],INVALID] ORTE_ERROR_LOG: A
> system-required executable either could not be found or was not
> executable by this user in file
> ../../../../../../orte/mca/ess/singleton/ess开发者_StackOverflow社区_singleton_module.c at
> line 357 [ip-10-99-75-58:02212] [[INVALID],INVALID] ORTE_ERROR_LOG: A
> system-required executable either could not be found or was not
> executable by this user in file
> ../../../../../../orte/mca/ess/singleton/ess_singleton_module.c at
> line 230 [ip-10-99-75-58:02212] [[INVALID],INVALID] ORTE_ERROR_LOG: A
> system-required executable either could not be found or was not
> executable by this user in file ../../../orte/runtime/orte_init.c at
> line 132
> --------------------------------------------------------------------------
> It looks like orte_init failed for some reason; your parallel process
> is likely to abort.  There are many reasons that a parallel process
> can fail during orte_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):
> 
>   orte_ess_set_name failed   --> Returned value A system-required
> executable either could not be found or was not executable by this
> user (-127) instead of ORTE_SUCCESS
> --------------------------------------------------------------------------
> --------------------------------------------------------------------------
> 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):
> 
>   ompi_mpi_init: orte_init failed   --> Returned "A system-required
> executable either could not be found or was not executable by this
> user" (-127) instead of "Success" (0)
> --------------------------------------------------------------------------
> *** The MPI_Init() function was called before MPI_INIT was invoked.
> *** This is disallowed by the MPI standard.
> *** Your MPI job will now abort.
> -------------------------------------------------------------------------------------------

First of all, it looks to me as an Open MPI error. But I installed MPICH 2 and not Open MPI.

Secondly, I am at a fix on how to handle this as all help seems to be directed to Open MPI users. Am I missing something?

I have the same problem on Ubuntu 12.04. I find my problem is because I have both open-mpi and mpich2 on my computer. When I compile my program using mpicc, it will be linked to open-mpi not mpich2. To fix this problem, you can use "mpicc.mpich2" to compile your program and then use "mpiexec.mpich2" to execute your code.

Indeed, these error messages are all Open MPI errors. For some reason, you appear to also have a (badly configured?) copy of Open MPI installed somewhere. You can check which particular file you are executing when you type mpiexec by running which mpiexec. I believe that you can compare this with the result of:

dpkg --listfiles mpich2

(or similar) in order to figure out where the MPICH2 package was installed.

I had this happen to me, and I found the issue. Somewhere on your system during startup LD_PRELOAD was set to point to libmpi.so in OpenMPI.

Example:

export LD_PRELOAD=<some_directory>/openmpi/1.4.4/lib/libmpi.so

The result is that MPICH2 fails. Just do 'unset LD_PRELOAD' before running MPICH2 and the issue goes away.

Note that setting LD_PRELOAD to OpenMPI's libmpi.so is actually required sometimes for OpenMPI to work, so unsetting may break OpenMPI for you. Just remember to reset it if you need to use OpenMPI.