cfdof workbench

A subforum specific to the development of the OpenFoam-based workbenches ( Cfd https://github.com/qingfengxia/Cfd and CfdOF https://github.com/jaheyns/CfdOF )

Moderator: oliveroxtoby

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A.Ahmad
Posts: 3
Joined: Wed May 18, 2022 12:29 am

cfdof workbench

Post by A.Ahmad »

hello, please am using freecad 0.20.2 appimage on linux (pop os). I am trying to run cfdof simulation. After setting up, I tried to run the solver but it is giving me an error "here are not enough slots available in the system to satisfy the 4
slots that were requested by the application:
/usr/lib/openfoam/openfoam2206/platforms/linux64GccDPInt32Opt/bin/renumberMesh
Either request fewer slots for your application, or make more slots
available for use.
A "slot" is the Open MPI term for an allocatable unit where we can
launch a process. The number of slots available are defined by the
environment in which Open MPI processes are run:
1. Hostfile, via "slots=N" clauses (N defaults to number of
processor cores if not provided)
2. The --host command line parameter, via a ":N" suffix on the
hostname (N defaults to 1 if not provided)
3. Resource manager (e.g., SLURM, PBS/Torque, LSF, etc.)
4. If none of a hostfile, the --host command line parameter, or an
RM is present, Open MPI defaults to the number of processor cores
In all the above cases, if you want Open MPI to default to the number
of hardware threads instead of the number of processor cores, use the
--use-hwthread-cpus option.
Alternatively, you can use the --oversubscribe option to ignore the
number of available slots when deciding the number of processes to
launch."
please can someone help me through on how to change the number of slots?
KAKM
Posts: 109
Joined: Tue May 04, 2021 12:17 am

Re: cfdof workbench

Post by KAKM »

Do you want to change the number of slots your machine has available or the number of slots CfdOF requests?
herbk
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Location: Windsbach, Bavarya (Germany)

Re: cfdof workbench

Post by herbk »

Hi,
It's for openSuse, but may be it works at other Linux Distros to:

viewtopic.php?t=76629
Gruß Herbert
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oliveroxtoby
Posts: 812
Joined: Fri Dec 23, 2016 9:43 am
Location: South Africa

Re: cfdof workbench

Post by oliveroxtoby »

A.Ahmad wrote: Mon Mar 27, 2023 4:35 pm hello, please am using freecad 0.20.2 appimage on linux (pop os). I am trying to run cfdof simulation. After setting up, I tried to run the solver but it is giving me an error "here are not enough slots available in the system to satisfy the 4
slots that were requested by the application:
This should just mean that you need to reduce the 'Parallel Cores" in the CfdSolver object properties as it exceeds the number available on your machine. I'm a bit surprised there are not four cores available though.
herbk
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Joined: Mon Nov 03, 2014 3:45 pm
Location: Windsbach, Bavarya (Germany)

Re: cfdof workbench

Post by herbk »

Hi Oliver,
oliveroxtoby wrote: Wed Apr 05, 2023 3:24 pm I'm a bit surprised there are not four cores available though.
I have had the same message at a two 6 cores/8 threads laptops and had to switch off multicore use to get a output.
In my mind the prob ist based at changend pakge contend of OpenMPI. After installing openmpi1-devel (where i'm in mind i havn't installed it at older systems) multicore use runs.
Cfdof also needs openmpi1 (wich is a bit old ;) ), - by default openSuse installs openmpi4, where is cfdof not working with.
Gruß Herbert
A.Ahmad
Posts: 3
Joined: Wed May 18, 2022 12:29 am

Re: cfdof workbench

Post by A.Ahmad »

Thank you all for your help, I did not visit may page for sometime, I was able to solve the problem by turning the parallel option at the cfdsolver data panel "false".
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