[chris0815]

Dear all,


I am currently running a transient simulation that requires me to save a large number of individual time steps. In order to avoid annoying our administrators I tried using the collated fileHandler option. While case setup, decomposition and post-processing work perfectly, the decomposition of a recomposed case does not.


I have now experimented with some tutorial cases as I suspected that the problem lies with the dynamic mesh.


Specifically, I ran the surfaceMountedCube and simpleRotor cases using the collated I/O option. While there are no problems with the surfaceMountedCube, the simpleRotor case reproduced the error I am getting on my actual case when trying to decompose again:

                         [simpleRotor]$ decomposePar -latestTime -fileHandler collated
 /*---------------------------------------------------------------------------*\
 | =========                 |                                                 |
 | \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
 |  \\    /   O peration     | Version:  2306                                  |
 |   \\  /    A nd           | Website:  www.openfoam.com                      |
 |    \\/     M anipulation  |                                                 |
 \*---------------------------------------------------------------------------*/
 Build  : _fbf00d6b-20230626 OPENFOAM=2306 version=2306
 Arch   : "LSB;label=32;scalar=64"
 Exec   : decomposePar -latestTime -fileHandler collated
 Date   : Oct 17 2025
 Time   : 08:52:54
 Host   :  
 PID    :  
 I/O    : collated [unthreaded] (maxThreadFileBufferSize = 0).
          Writing may be slow for large file sizes.
 Case   : /collatedTest/simpleRotor
 nProcs : 1
 trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
 fileModificationChecking : Monitoring run-time modified files using timeStamp (fileModificationSkew 5, maxFileModificationPolls 20)
 allowSystemOperations : Allowing user-supplied system call operations
 
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 Create time
 
 
 Overriding OptimisationSwitches according to controlDict
     fileHandler (unregistered)
     maxThreadFileBufferSize 2e+09;
 
 
     maxMasterFileBufferSize 2e+09;
 
 
 
 
 
 
 Decomposing mesh
 
 
 Create mesh
 
 
 Calculating distribution of cells
 Decomposition method hierarchical [3] (region region0)
 
 
 Finished decomposition in 0 s
 
 
 Calculating original mesh data
 
 
 Distributing cells to processors
 
 
 Distributing faces to processors
 
 
 Distributing points to processors
 
 
 Constructing processor meshes
 Overriding OptimisationSwitches according to controlDict
     fileHandler (unregistered)
     maxThreadFileBufferSize 2000000000;
 
 
     maxMasterFileBufferSize 2000000000;
 
 
 
 
 Processor 0
     Number of cells = 2069
     Number of points = 4422
     Number of faces shared with processor 1 = 108
     Number of processor patches = 1
     Number of processor faces = 108
     Number of boundary faces = 4310
 Overriding OptimisationSwitches according to controlDict
     fileHandler (unregistered)
     maxThreadFileBufferSize 2000000000;
 
 
     maxMasterFileBufferSize 2000000000;
 
 
 
 
 Processor 1
     Number of cells = 2069
     Number of points = 4560
     Number of faces shared with processor 0 = 108
     Number of faces shared with processor 2 = 108
     Number of processor patches = 2
     Number of processor faces = 216
     Number of boundary faces = 4338
 Overriding OptimisationSwitches according to controlDict
     fileHandler (unregistered)
     maxThreadFileBufferSize 2000000000;
 
 
     maxMasterFileBufferSize 2000000000;
 
 
 
 
 Processor 2
     Number of cells = 2070
     Number of points = 4424
     Number of faces shared with processor 1 = 108
     Number of processor patches = 1
     Number of processor faces = 108
     Number of boundary faces = 4312
 
 
 Number of processor faces = 216
 Max number of cells = 2070 (0.03221649485% above average 2069.333333)
 Max number of processor patches = 2 (50% above average 1.333333333)
 Max number of faces between processors = 216 (50% above average 144)
 
 
 Time = 0.02
 
 
 Processor 0: field transfer
 Overriding OptimisationSwitches according to controlDict
     fileHandler (unregistered)
     maxThreadFileBufferSize 2000000000;
 
 
     maxMasterFileBufferSize 2000000000;
 
 
 Detected additional non-decomposed files in "/collatedTest/simpleRotor/0.02/uniform"
 Processor 1: field transfer
 Overriding OptimisationSwitches according to controlDict
     fileHandler (unregistered)
     maxThreadFileBufferSize 2000000000;
 
 
     maxMasterFileBufferSize 2000000000;
 
 
 
 
 
 
 --> FOAM FATAL IO ERROR: (openfoam-2306)
 incorrect first token, expected <int>, found on line 26: error
 
 
 
 
 file: processors3/0.02/meshPhi at line 26.
 
 
     From Foam::Istream& Foam::List<T>::readList(Foam::Istream&) [with T = char]
     in file primitives/chars/lists/charList.C at line 103.
 
 
 FOAM exiting
  p { margin-bottom: 0.1in; line-height: 115%; background: transparent }

While I could just preserve the decomposed case for later restarts, I would not be able to change the setup e.g. boundary conditions between runs in this way, as the collated decomposed files are not editable (https://www.openfoam.com/news/main-n...v1712/parallel)


Have any of you encountered this problem before and if so, is there a solution?






Kind regards,
Chris