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-   -   star-cd parallel problem (http://www.cfd-online.com/Forums/star-cd/74381-star-cd-parallel-problem.html)

moro March 31, 2010 04:21

star-cd parallel problem
 
Hi Community,

I have some problems when I like to run star in the parallel mode with one node and four cpu's.
The mesh has about 2million polyhedrical cells.
I start star with the follow command:

star -dp -mpi=mpich mypc,4

or

star -dp -mpi=hp mypc,4

At first the calculation begins but after some time I get for both cases this message:

[
2 ] ***Received signal 11 - EXITING
*** PROCESSOR 2 WILL STOP PROCESS NOW
MPI Application rank 1 exited before MPI_Finalize() with status 13
[ 1 ] ***Received signal 15 - EXITING
[ 4 ] ***Received signal 15 - EXITING
[ 3 ] ***Received signal 15 - EXITING
*** PROCESSOR 3 WILL STOP PROCESS NOW
*** PROCESSOR 1 WILL STOP PROCESS NOW
*** PROCESSOR 4 WILL STOP PROCESS NOW


Have you perhaps any idea which can help me?

Thank you very much for your help.

dingning April 29, 2010 10:59

Hi,moro. I think you should not use this method for parallel. because only one PROCESSOR can get the information. you can try to use batch.

sdwijeya April 30, 2010 09:49

I don't see you are issuing a decomposing command.

Try

star -dp -mpi=mpich -decompmeth=x mypc,4

-decompmeth = x : automatical decomposing
-decompmeth = s : using .set file
-decompmeth = m: manual, by user

Sameera

moro May 4, 2010 02:39

I thought that when i write the star -command without the '-decompmeth', star will used the standard decomposition method: metis
But I don't know, is it really necessary to write?
Sorry, but I am a beginner in CFD and have not really experience with star.

Thank you for your help.

moro May 4, 2010 03:12

Quote:

Originally Posted by dingning (Post 256871)
Hi,moro. I think you should not use this method for parallel. because only one PROCESSOR can get the information. you can try to use batch.

Can you perhaps explain me the batch mode a little bit more accurately.What does the batch mode do in combination with the star command?

-batch Generate script for submission to batch queueing systems.

Thank you very much.


sdwijeya May 4, 2010 08:31

The command I posted before was for parallel computing NOT for Batch mode which requires queuing. You have to specify the command decompmeth for star to do the decomposition.

All these commands are in the Appendices section of the user guide.

All the best

TomK May 12, 2010 19:18

When I submit a job on multiple processors I use the command:

star -dp computername,numberofprocessors

so, as example:

star -dp star01,4

This has the mpi set to default and the decomp set to default. I find that the default settings work on versions 3.26 and higher. Sometimes if you are trying to decompose a file that is too big (for example you are on a 32 bit system), you may have to decompose in a seperate step;

star -decomp,4 (I forget whether the ',' is necessary)

Then, to execute do

star -dp -nodecomp star01,4

If you are using the same geometry file for another run and only changing the problem file, then you can save a little time using the nodecomp option.

Hope this helps,

Tom

moro May 18, 2010 02:50

Hi Tom,

At first thank you for your answer.
Get it right, that the reason for my mpi problem is that my case is to big?

Have I the opportunity to change some parameter in the case.param file during the run of my case in star? Apply star this change directly?

Thank you very much


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