CFD Online Discussion Forums - Restarting a case using latestTime in parallel

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Restarting a case using latestTime in parallel

Hi there,

I'm a bit confused about post-processing or restarting a case that's been run in parallel. I am currently running a large simulation on a cluster over 24 processors. However, my space is limited so I ran the case for the first half of the time I plan to run it, and then I was going to begin the second simulation from the latestTime after removing the earlier data.

What I'm confused about is: if the case has been deconstructed over 24 processors, should I remove the time steps (except for the last one) from each individual processor and keep the case decomposed before running? Or else, reconstruct the case completely, keep the latest time, remove all of the processor directories, set the time in controlDict to latestTime and start again from the beginning (including deconstructing the case, etc).

Does anyone have experience with this and can offer advice?

Thanks in advance!

Ariel

You can reconstructPar -latestTime so you have your reconstructed case directory. Then you can delete or move elsewhere all the 24 folders of the early decomposed case. Then use deconstructPar again making sure that in your controlDict file you set start from latestTime and not startTime.

Hi @Pervispasco,

Thanks very much for your answer. I tried this on a small test case and it worked well. However, I'm having some trouble now using the same method for a much larger case spread across 24 processors. I am getting the error:

Code:

--> FOAM FATAL IO ERROR: 

error in IOstream "/ichec/work/uceng004c/case1/221.6/nut" for operation Ostream& operator<<(Ostream&, const char)



file: /ichec/work/uceng004c/case1/221.6/nut at line 18.



    From function IOstream::check(const char*) const

    in file db/IOstreams/IOstreams/IOstream.C at line 99.



FOAM exiting

I checked though and all of the data does look like it was saved correctly so I don't understand why it won't work?

Also, I am trying to view the solution in paraview for one of the processors, so I tried (from within the specific processor directory):

Code:

touch processor9.OpenFOAM

Which did create the file, but did not transfer of the fields so again, I'm quite confused if there's some problem in saving the fields...

Again, any help or advice is greatly appreciated.

Regards,
Ariel