[Simbelmynë]

Hey,


So installing OFv6 on an Ubuntu-based cluster is quite easy. However, since I also wish to have a working setup of ANSYS on the cluster I would like to configure this with CentOS 7.x instead. *)


Do you compile OF from source and try to find and install the dependencies from outside of the official repositories or do you use a Docker swarm?



*) So an Ubuntu 16.04 setup would work with both OFv6 and ANSYS, but seeing that it only has 2 more years of security updates I would rather have either CentOS or Ubuntu 18.04. However this is what I will use if there is no easy solution to the problem.


Btw, I think it is mind-boggling and sad that a company with the size of ANSYS cannot maintain a working Debian release.

[wyldckat]

Quick answer: Step-by-step installation instructions to build OpenFOAM 6 on CentOS 7 are provided here: https://openfoamwiki.net/index.php/I...7.5_.281804.29 - they are not the official instructions, so please let me know here if you have problems when following them.

Edit: This to say that it's preferable to build from source code.

[Milan2013]

I'd appreciate an advice on a similar matter from someone with experience.
We are setting up at work a workstation (4 x 18-core CPU's 256 GB RAM, to be updated later with 2 extra GPU's and more memory - if that matters at all for the question here). In order to use both ANSYS and OpenFoam, we can choose between these options:

1. Install one OS and use both. The Linux choices that fit ANSYS are:
SuSE Linux Enterprise Server & Desktop 12 (SP2 & SP3)
CentOS 7 (Community Enterprise OS 7.3, 7.4 & 7.5)

2. Perhaps use virtual machines? i.e. install windows, and than create one or more virtual machines with probably Ubuntu, to use OpenFoam on it. I wonder if this solution has its drawbacks? Like slowing down the computation performance...?

So we were opting for option 1, to keep things simple, with CentOS 7 as OS.

But I have received different opinions on what to do, with some concerns from an experienced developer in terms of "difficulties compiling the OpenFoam under CentOS and Red Hat"...the issue being is "is they stick to hugely outdated versions of critical software like GCC"...and in addition "... SuSE is probably safer because some developers use it internally, so it gets tested. And it has a more progressive release strategy."

Any advice on what choice is optimal here, is appreciated greatly!

[Simbelmynë]

@Milan2013


If your primary ANSYS package is Fluent then you can setup the problem in a virtual machine (ANSYS Meshing is the only thing that does not work under Ubuntu 18.04). You can then transfer the project files to Ubuntu and run the simulation there. This way you will make sure that you can utilize all the resources of your computer (virtualization affects performance). OpenFOAM will run without a hassle on Ubuntu 18.04 and you will have a much more up-to-date system for other work tasks. If the workstation will only be used for number-crunching then you will most likely setup the problems on another station and just submit the jobs, then you just need a working Fluent and OpenFOAM installation.



Another option is to use Windows 10 and install ANSYS there. Since Windows store now has an Ubuntu Terminal for download you can actually run OpenFOAM quite easily through that, with less performance degradation compared to virtualization (depending on the amount of file I/O you do). I have not done any extensive testing on performance though so this is just from Phoronix tests. Post-processing might be less fun though with this setup, but in theory you should be able to install Paraview in the Ubuntu terminal and then install X on Windows to execute it (Xming for instance).

Then again, you can also use CentOS and compile the necessary sources that you need. Like the latest gcc, etc. Don't be afraid of the CentOS old kernel version, it has evolved past the release schedule of the linux kernel. Mainline linux kernel enabled EPYC at version 4.8, but the long term support versions of linux has their own patches to the kernel.


https://community.amd.com/thread/226108

[wyldckat]

Quick additions to Simbelmynë's answer:

1. CentOS 7 + SCL: https://wiki.centos.org/AdditionalRe...positories/SCL - and you won't fret over missing more recent GCC compilers or Python versions.
   • If you take a look at this page: https://openfoamwiki.net/index.php/I...CentOS_SL_RHEL - you'll even see two possible approaches, with and without SCL.
2. SLES/SLED 12: I'm not familiar with it, but it's a fairly valid alternative (it's the SuSE's alternative to RHEL).
   • I'm not familiar with it: this also means that I haven't written much on the wiki pages about it when it comes to installing OpenFOAM
3. Beyond this, CentOS 8 should be popping up in a few months...
4. Steer clear from virtual machines in a cluster environment, at least when dealing with CFD software. Adding that level of complexity to the infrastructure will not bring you physical and mental health.
   • That said, virtualization may be useful for making it easier for mixing and matching the needs of the users... in which case, Docker-like containers would likely be the better alternative... but still...
5. Which reminds me, there are at least a couple of package management projects for clusters... but I can't remember neither one of them... a bit of searching and it's Spack and EasyBuild.

[Milan2013]

Thanks everyone for the helpful suggestions!
M.