Actually, I had the same problem but I may say the problem was solved by using FieldConvert in serial, otherwise by using IncNavierStokesSolver in parallel. I mean, one can obtain a single vtu (or plt) file, even if there are multiple chk (or fld) "files in folders" generated in parallel FieldConvert, by converting multiple files into a single output file by applying a "one-time-only" serial run.

However, it should be noted that this makes the process longer, but may help your problem. (e.g., I am working with more than 250 processors, producing big data, using this method to get results and it works.)

Kimden: stanislaw.gepner@pw.edu.pl;

Kime: nektar-users@imperial.ac.uk; - 11/06/22 - 05:49

Konu: Re: [Nektar-users] Parallel FieldConvert output in one single vtu file ?

Ho Saad,

You could try to produce a .plt file (a binary Tecplot format), and if your PV support it read this in. The benefits of plt files is size, and that it is a single file. With the PV support for plt. It used to be, that you needed to compile PV to use it, but I think now it is in the binaries (at least on Ubuntu).

Cheers,
Stan

On 11.06.2022 11:24, Debbahi Saad wrote:

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Hi All,

I'm on Nektar version 5.1.0, ending with datasets composed of moderate size files in numbers reaching few hundreds using the Incompresible Navier-Stokes Solver,

I just want to use parallel FieldConvert to speed up the conversion process (which actually provide a real gain in speed) and produce a single vtu file, since opening *.pvtu format datasets gave an error in paraview-openmpi-5.9.1 ,

The command I'm using for parallel FieldConvert looks like this:

mpirun -n 16 FieldConvert -m mapping model.xml model_i.chk model_i.vtu

this creates n .vtu files under a .pvtu header, which as I reported earlier gives rise to this error:

ERROR: In /builddir/build/BUILD/ParaView-v5.9.1/VTK/IO/XML/vtkXMLPDataReader.cxx, line 315

vtkXMLPUnstructuredGridReader (0x55ffb1431450): File for piece 0 cannot be read.

Is it possible to produce one single .vtu file out of parallel FieldConvert ?

Thanks in advance, any help on this or workaround will be really appreciated,

Kind regards,

Saad
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