Requirements.md

OpenFOAM® System Requirements

OpenFOAM requires a functioning C++14 compiler and GNU make build toolchain.

Minimum recommended versions

• gcc : 7.5.0 (minimum, not necessarily recommended)
• cmake: 3.8 (required for ParaView and CGAL build)
• boost: 1.48 (required for CGAL build and some functionality)
• fftw: 3.3.7 (recommended - required for FFT-related functionality)
• paraview: 5.6.3 (for visualization)

If using the Intel® compiler, 17.0.1 20161005 is the minimum usable version.

To check the installed versions

Program	To check the version
gcc	gcc --version
clang	clang --version
icc (intel)	icc --version
cmake	cmake --version
openmpi	orterun --version

Cautionary note for system openmpi

When using system openmpi, some caution is required due to the openmpi issue 5375 that affected several versions of the openmpi2 or openmpi3 series.

series	major/minor	Minimum version
openmpi1	all	not affected
openmpi2	2.0	avoid this series
openmpi2	2.1	2.1.6
openmpi3	3.0	3.0.4
openmpi3	3.1	3.1.4
openmpi4	all	not affected

Additional utilities

• flex : not 2.6.2, 2.6.3 (fails for building scotch)
• m4 : no known minimum level
• QT : 5.9 (optional - for ParaView build)

Ubuntu (eg, 22.04)

Install dependencies by executing the following lines on the command line:

sudo apt-get update
sudo apt-get install build-essential autoconf autotools-dev cmake gawk gnuplot
sudo apt-get install flex libfl-dev libreadline-dev zlib1g-dev openmpi-bin libopenmpi-dev mpi-default-bin mpi-default-dev
sudo apt-get install libgmp-dev libmpfr-dev libmpc-dev

To inspect the available system versions, use the apt-cache show command. For example,

sudo apt-cache show libopenmpi-dev

Program	Ubuntu	Program version
gcc	22.04	11.3.0
openmpi	22.04	4.1.2
cmake	22.04	3.22.1
flex	22.04	2.6.4
m4	22.04	1.4.18

If you intend to use system components, you can also install the following:

apt-get install libfftw3-dev libscotch-dev libptscotch-dev libboost-system-dev libboost-thread-dev libcgal-dev

Program	apt-cache show	Ubuntu	Version
boost	libboost-dev	22.04	1.74.0
CGAL	libcgal-dev	22.04	5.4.1
FFTW	libfftw3-dev	22.04	3.3.8
scotch	libscotch-dev	22.04	6.1.3

Some libraries can be installed from the operating system, or compiled from the ThirdParty directory. The default configuration for OpenFOAM assumes OpenMPI from the system and ThirdParty installations for most others (boost, CGAL, FFTW, Kahip, Scotch). This is generally the most portable configuration across various Linux distributions, but it may be desirable to use more system libraries on Ubuntu.

openSUSE (eg, Leap-15.4)

Install the dependencies by copying and pasting the following lines to the command line:

sudo zypper install -t pattern devel_C_C++
sudo zypper install cmake gnuplot flex libfl-devel readline-devel zlib-devel openmpi4-devel
sudo zypper install gmp-devel mpfr-devel mpc-devel

If you intend to use system components, you can also install the following:

sudo zypper install fftw3-devel libboost_system-devel libboost_thread-devel

but note that scotch and cgal are only available via the science repository. For boost, you may need to specify a specific version. For example,

sudo zypper install fftw3-devel libboost_system1_75_0-devel libboost_thread1_75_0-devel

This installs

Program	openSUSE	Program version
gcc	15.4	7.5.0
openmpi	15.4	2.1.6
openmpi	15.4	4.1.1
cmake	15.4	3.20.4
flex	15.4	2.6.4
m4	15.4	1.4.18

OpenMPI

Check that the openmpi installation can be found:

orterun --version

And the command mpicc --show should display a complete compilation line. This information is used in OpenFOAM to obtain the compilation and link options.

For openSUSE it is common that this command cannot be found. The reason being that the operating system can have several different MPI vendors and versions installed and the user or sysadmin needs to defined the preferred MPI. For this task, the mpi-selector and mpi-selector-menu programs are used. These are automatically installed by the system when openmpi has been installed.

If openmpi has been selected, the output will resemble the following:

$ mpi-selector --query

default:openmpi
level:user

If this is not the case, the mpi-selector-menu can be used to define the preferred default.

Note that changes in the preferred MPI do not take effect until the next login.

If all else fails, a brute force solution can also be used by simply adding the corresponding lines to the $HOME/.bashrc file:

export PATH=$PATH:/usr/lib64/mpi/gcc/openmpi/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib64/mpi/gcc/openmpi/lib

This solution is not particularly nice, but may also be necessary if some other part of the operating system installation is incomplete.

Using IntelMPI

To run with IntelMPI, the LD_PRELOAD environment variable can be used to pre-load the appropriate Intel® MPI binding library. For more details, see INTELMPI release note page 13. The following line can be the $HOME/.bashrc file:

export LD_PRELOAD="libmpi.so"

Additional libraries

When compiled ParaView from source additional dependencies will be required. A partial list is given in the ThirdParty requirements.

However it is recommended to skipped this initially since it generally represents the main compilation difficulty encountered. In many cases, a system installation of paraview or a precompiled binary will be much easier and likely fully adequate for your needs.

Since any ParaView/VTK dependencies are isolated within the visualization module, it is always possible to compile plugins for different ParaView versions as well as different VTK/Mesa combinations at any later stage without recompiling OpenFOAM itself.

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