Parallel computing by OF 2.2.0
 

hi
I APOLOGIZE for my simple problem and new thread. I posted my problem http://www.cfd-online.com/Forums/ope...ocessor-2.html but nobody answered me !! however I repeat it :

I tried to parallel computing (OF 2.2.0)by two desktop computers. but this error was exposed.

I do decomposepar on host machine and machines file contains two line (full names of two machines) and network is OK.
is correct this command ?( mpirun --hostfile /home/ali/machines.txt -np 20 icoFoam -parallel > test &)
others Threads confused me , what should I do ? (step by step)

Greetings Ali,

Since you asked this in a new thread, I deleted the old post, to avoid confusion by future readers.

OK, as for your problem, can you please share the file "machines.txt"? Because from the error message, it's inside that file that the problem is located.

Best regards,
Bruno

thanks ,Bruno.
ACCEPT MY APOLOGIZE FOR DELAY, please. I was very busy.

has a specific path machines file ?:o

Hi Ali,

If you are using Open-MPI, then the problem is that you are using the keyword "cpu" when it should be "slots". This is explained here:
http://www.open-mpi.org/faq/?categor...imple-spmd-run

Best regards,
Bruno

Thanks for quick reply.
I changed the keyword but it dose not work. I read all of the page and I tried to do the orders. but I get no result !!
is NFS passwordless config. necessary for parallel computing ?

Hi Ali,

NFS doesn't need password. It's the usual folder sharing system used on Linux Distributions.

Folder sharing is necessary for running OpenFOAM in parallel with more than one machine.

I think I'm assuming that you are using Open-MPI, but you might not be using it at all. Please run the following command:
Best regards,
Bruno

my open mpi ver. is 1.4.3
-------------------------
Dear Bruno , I ran openfoam on multi core PC but I confused about cluster because Im not familiar with linux !
what is your idea about these steps ?
1. setup openfoam on all PCs.
2. config. sshd and ssh files on servers and client.(PasswordAuthentication no)
3. share home folder between PCs with ssh.
4. create a machines file that include PCs name and ip addresses.
5. using mpirun command , explained at openfoam guide.
and a questions :
do I need to add some lines in ./bachrc or ./profile files for parallel computing?

Parallel
 

hi

I want to run parallel OpenFoam 2.2.x on two node , I read openfoam user guide and try to do its order, but the guidelines dont explain it completely. please give me some advises about the steps that I sould do for doing this aim in openfoam and ubuntu .
Note : I can run openfoam on multi core system and I familiar with MPI .
clearly I want to know :
1) are ssh and sshd config. on ubuntu necessary ? (if yes how)
2) do I need hard disk sharing between machines ?
3) is decomposePar similar to multicore run ?
4) must I setup openfoam on all machines?
5) how do openfoam find <machines> file address ? (in other words where do I put machines file in hard disk ?)
in advance, thanks for your guides.

Hi Ali,

1. Yes, you have to set-up OpenFOAM on all nodes that are going to use it, or at least share the folder where it is installed in the master node.
2. My advice is to use password-less SSH keys within the cluster network. No need to modify the "sshd_config" file.
3. Either share the folders in the home folder using NFS v4, or use the strategy mentioned here: Running OpenFOAM in parallel with different locations for each process
4. The "machines" file should only have the host names of each machine or the IP for that machine. Not both.
   • That's actually one thing I forgot to ask you to try: replace the names with the IP addresses of the machines in the "machines.txt" file. Because I think that the problem is that the machines had a "-" symbol in their names, leading to the error message. But I haven't managed to test this myself.
5. You can use mpirun or foamJob. For more information, run:
   
   Code:

   ---

   foamJob -help

   ---

6. If you use foamJob, you don't need to change the ".bashrc" files, as long as OpenFOAM is installed in the same path on all machines. But if you use mpirun, you should define the same source command on your ".bashrc" file on all your clusters.

For more information, have a look into this blog post of mine: Notes about running OpenFOAM in parallel

Best regards,
Bruno

Greeting all,
can somebody plz suggest me the link there i will get the experimental data to validate the results for the Sandia -CH4H2N2 . similar to the tutorial . i tried to search but not able to found .

Thank you ,
Regards ,
Payal .

Google keyword sandia flame...

http://www.sandia.gov/TNF/DataArch/SANDchn.html