> On 13 Nov 2018, at 10:11, Chris Eldred <chris.eldred@gmail.com> wrote:
>
> Hey Lawrence,
>
> I followed the advice at https://github.com/firedrakeproject/firedrake/issues/1325 and used
> sudo update-alternatives --config mpi
> sudo update-alternatives --config mpirun
> to select mpich instead of openmpi.
>
> Now mpicc -show gives
> gcc -Wl,-Bsymbolic-functions -Wl,-z,relro -I/usr/include/mpich -L/usr/lib/x86_64-linux-gnu -lmpich
> which seems right.
>
> But when I run in parallel using
> mpirun -n X python3 foo.py
> it simply runs (as noted in the issue referenced above) X copies of foo.py in serial.
>
> What is the correct way to get Firedrake working in parallel on Ubuntu 18.04?
>
> Also, I would suggest writing up some instructions and putting them on the website (I am happy to do this) since the "obvious" approach of mpirun -n X python3 foo.py has a nasty and non-obvious failure mode.

You also need to rebuild firedrake to link against MPICH.

Run with firedrake-install --no-package-manager

...

Cheers,

Lawrence