Last updated: 2023-11-11
Rocky 8 is a modern Linux distribution that is similar and supersedes CentOS 7. It comes with newer versions of software tools and system libraries, which means that more software will install out of the box without having to go an extra mile to get them installed. We expect a lot of things to keep working as before, but some software tools may require you to tweak your scripts and to re-install for instance R and Python packages.
Here are some of the hurdles you may run into:
Software Repositories : Not all, but the majority of the existing built-in, CBI, and Sali environment modules work also on Rocky 8. A small number of modules specific to CentOS 7 have been removed from Rocky 8. Many of the modules are no longer necessary to use on Rocky 8, because they provided software and libraries that were otherwise outdated on CentOS 7. In contrast, Rocky 8 comes with newer versions making the need for loading newer versions via modules less necessary - when in doubt, try first without loading the module.
Software Collections (SCL) : Compared to CentOS 7, Rocky 8
provides only SCLs for using modern GCC development tools, e.g. C
and C++ compilers. These SCLs, called
somewhat to the
devtoolset SCLs that are available on CentOS 7.
The built-in GCC version is now 8.5.0 (2021-05-14), whereas on
CentOS 7 it was 4.8.5 (2015-06-23). Python and Ruby SCLs are no
pythoncommand; Python 3 has to be called as
python3and legacy Python 2 is available as
python2. On CentOS 7,
python2. Python 3.6 is available via
python3.6, Python 3.8 via
python3.8, and Python 3.11 via
/opt/rh/rh-python38/root/usr/bin/python3: bad interpreter: No such file or directorywhen you run a Python based software, then you need to reinstall that software tool.
MPI : OpenMPI is available via the built-in module
mpi. On Rocky
8, the default, and only available version is OpenMPI 4.1, which you
get via module
mpi/openmpi-x86_64 (sic!). Note that, on CentOS 7,
mpi/openmpi-x86_64 provided legacy OpenMPI 1.10. On CentOS 7,
there was also
mpi/openmpi3-x86_64 for OpenMPI 3.1. Because Rocky
8 and CentOS 7 have no versions of OpenMPI in common, it is likely
that software tools that were compiled with OpenMPI as a dependency
have to be rebuilt for Rocky 8.