[Nek5000-users] run-time hang up in gs_setup

[nek5000-users at lists.mcs.anl.gov]

Hi Azad,

You are in record-setting territory for element counts! :)

Are you using the amg-based coarse-grid solver?
It is certain that you will need to do this (and,
therefore, you will need matlab to process the AMG 
operators).   There is some discussion of the steps
on the wiki page.  We can walk you through this process
if you have any questions.

What value of lx1 are you using?

I would recommend fewer elements and a higher value of lx1.
I think it will be easier to manage the data, etc.

Paul





On Tue, 10 Jan 2012, nek5000-users at lists.mcs.anl.gov wrote:

> Dear NEKs;
>
> I am trying to run a simulation of a turbulent flow in a straight pipe
> in high Reynolds number (Re_tau = 1000). After generating the grid with
> PRENEK and extrude it using n2to3, the mesh ended up with 4,495,920
> elements. It compiled properly; however, trying to run it, hanged up in
> the last stage:
> ########################################################################
>
> verify mesh topology
>   -1.000000000000000         1.000000000000000       Xrange
>   -1.000000000000000         1.000000000000000       Yrange
>    0.000000000000000         25.00000000000000       Zrange
> done :: verify mesh topology
>
>  E-solver strategy:  1 itr
> mg_nx:            1            3
> mg_ny:            1            3
> mg_nz:            1            3
> call usrsetvert
> done :: usrsetvert
>
> gs_setup: 866937 unique labels shared
>   pairwise times (avg, min, max): 0.000241442 0.00019722 0.000265908
>   crystal router                : 0.000458177 0.000445795 0.000471807
>   used all_to_all method: pairwise
>   setupds time 5.6048E-02 seconds   1  2     4565612     4495920
>   setvert3d:   4    86046564   122013924    86046564    86046564
> call usrsetvert
> done :: usrsetvert
>
> gs_setup: 8041169 unique labels shared
>   pairwise times (avg, min, max): 0.00050716 0.000427103 0.00056479
>   crystal router                : 0.0040165 0.00392921 0.00411811
>   used all_to_all method: pairwise
>   setupds time 1.0465E+00 seconds   2  4    86046564     4495920
> setup h1 coarse grid, nx_crs=            2
> call usrsetvert
> done :: usrsetvert
>
> gs_setup: 866937 unique labels shared
>   pairwise times (avg, min, max): 0.000233683 0.000197816 0.00024941
>   crystal router                : 0.000466869 0.00045588 0.000478101
>   used all_to_all method: pairwise
> ########################################################################
>
>
> I was wondering if you could help me with that. I attached the run
> logfile and also genmap.out.
>
> Many thanks
> Azad
>