Parallel Computing in a local network
 

Hi dear FOAMers,

I want to use two computers in a local network in order to make my calculations in OpenFOAM 2.2 much faster.
I wish to run the calculations from cfd4 on the machines cfd3 and cfd4, which both have 4 processors (cpu), that means I want to use 8 cpus for the calculation. By the way I got the names of the computers by typing hostname in the terminal. The operating system on both computers is Kubuntu 12.04.
In order to run applications in parallel I followed the instructions given by http://www.openfoam.org/docs/user/ru...s-parallel.php .
So I first of all wrote the file "decomposeParDict" in order to break up the geometry and the field of my calculation in 8 subdomains. Afterwards I have written the file machines.
After creating the mesh and decomposing my mesh and field on cfd4 I typed

in order to get the process using the sprayFoam solver started.
Unfortunately I get the following error:

Hello Ray,

I had a very bad experience using OF on multiple machines so I started this thread.
I was mixing architectures and eventually I gave up. But! If you go through the thread there is a lot of troubleshooting related to mpirun you may be lucky enough to find your problem by following wyldckat's suggestions.

Hope it helps!

Hi Ray,

As far as I know, to be able to run in a local network, you have to:

1. Have the OpenFOAM installed in all the nodes you are willing to use, or in a shared (nfs) unit.
2. Have your user load the OpenFOAM environment by default by adding
source /path/to/foam_install_dir/etc/bashrc
to your ~/.bashrc
3. Have passwordless login by ssh to the nodes.

Hey guys thanks for your answer.

Dear onyir,

could you please describe in more detail point 2. Where shall I add this line and to which directory should it refer?

best regards

ray

Hi ray,

In order to use OpenFOAM, you have to load the environment by sourcing the configuration file.
For example, if you have OpenFOAM-2.2.0 installed in your home directory, you'll have to do
. /home/user/OpenFOAM/OpenFOAM-2.2.0/etc/bashrc
or
source /home/$user/OpenFOAM/OpenFOAM-2.2.0/etc/bashrc

To do that automatically for your user, you have to add that line (updating your OpenFOAM installation directory and version) to the file
/home/$user/.bashrc

i found my bashrc file in the following directory:

cfd4@cfd4:/opt/openfoam220/etc$

So do i have to add source/opt/openfoam220/etc/bashrc in the first line of my .bashrc - file?

best regards

You can add that line at the end of your .bashrc

oh now I know what you mean, but I already had that line added :(

i still get the same error:

mpirun was unable to launch the specified application as it could not find an executable:

Executable: sprayFoam

while attempting to start process rank 4.