mpiexec fails as MPI init aborts

Question

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 surp

Answer 1

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=/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.