problem Mesh Levels in parallel run

Numerical methods and mathematical models of Elmer
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mark smith
Posts: 213
Joined: 26 Aug 2009, 18:20
Location: Peterborough, England

problem Mesh Levels in parallel run

Post by mark smith »

Hi All,
OS Ubuntu 20.04
I'm trying to use Mesh Levels = 2 in the simulation section of a parallel run using 8 cores and iterative solvers for a coupled heat and fluid flow problem.
The simulation runs OK without the "Mesh Levels = 2" entry but with it Elmer crashes with the following output:

ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ELMER SOLVER (v 9.0) STARTED AT: 2021/05/17 23:32:02
ParCommInit: Initialize #PEs: 8
ParCommInit: Initialize #PEs: 8
ParCommInit: Initialize #PEs: 8
ParCommInit: Initialize #PEs: 8
ParCommInit: Initialize #PEs: 8
MAIN:
MAIN: =============================================================
MAIN: ElmerSolver finite element software, Welcome!
MAIN: This program is free software licensed under (L)GPL
MAIN: Copyright 1st April 1995 - , CSC - IT Center for Science Ltd.
MAIN: Webpage http://www.csc.fi/elmer, Email elmeradm@csc.fi
MAIN: Version: 9.0 (Rev: unknown, Compiled: 2021-05-07)
MAIN: Running in parallel using 8 tasks.
MAIN: Running with just one thread per task.
MAIN: MUMPS library linked in.
MAIN: Lua interpreted linked in.
MAIN: =============================================================
ParCommInit: Initialize #PEs: 8
ParCommInit: Initialize #PEs: 8
ParCommInit: Initialize #PEs: 8
LoadInputFile: Trying to read "Run Control" section only
MAIN:
MAIN:
MAIN: -------------------------------------
MAIN: Reading Model: baffels_parallel_channel.sif
LoadInputFile: Scanning input file: baffels_parallel_channel.sif
LoadInputFile: Scanning only size info
LoadInputFile: First time visiting
LoadInputFile: Reading base load of sif file
LoadInputFile: Loading input file: baffels_parallel_channel.sif
LoadInputFile: Reading base load of sif file
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
LoadInputFile: Number of BCs: 5
LoadInputFile: Number of Body Forces: 0
LoadInputFile: Number of Initial Conditions: 2
LoadInputFile: Number of Materials: 4
LoadInputFile: Number of Equations: 2
LoadInputFile: Number of Solvers: 4
LoadInputFile: Number of Bodies: 2
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
WARNING:: LoadInputFile: > Material 2 < not used in any Body!
WARNING:: LoadInputFile: > Material 4 < not used in any Body!
ElmerAsciiMesh: Base mesh name: baffels_parallel_channel_0.25x2/.
LoadModel: Creating hierarchy of meshes by mesh multiplication: 2
SplitMeshEqual: Elapsed REAL time: 0.0863 (s)
SParIterGlobalNumbering: PE: 3Max iterations exceeded
SParIterGlobalNumbering: PE: 7Max iterations exceeded
SParIterGlobalNumbering: PE: 1Max iterations exceeded
SParIterGlobalNumbering: PE: 5Max iterations exceeded
SParIterGlobalNumbering: PE: 8Max iterations exceeded
SParIterGlobalNumbering: PE: 6Max iterations exceeded
SParIterGlobalNumbering: PE: 4Max iterations exceeded
SParIterGlobalNumbering: PE: 2Max iterations exceeded

I get a similar output when trying from Windows 10?

I thought mesh refining was supposed to work for parallel runs?

I have also discovered that including: Element = "p:2" in the solver sections works OK for iterative solvers but wont work if I use MUMPS ?

Is there an explanation or work around ?
Thanks in advance
Mark
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