That may be true for RedHat It _was_ maybe true, kind of, sometimes: config files were not always marked as config files, for example. It's definitely no long

That may be true for RedHat It _was_ maybe true, kind of, sometimes: config files were not always marked as config files, for example. It's definitely no longer true now. On Fedora you run preupgrade. For RHEL point releases, yum. For RHEL major releases, you need to run a kickstart upgrade.