Although the RHEL 8 hasn’t yet been released, the RHEL 8 Beta is already available.
Here are some aspects of it:
- it uses the dnf command instead of yum with an identical syntax (yum is an alias for dnf),
- the file system Btrfs, once in technical preview, is no longer available,
- concerning the Python language used for most of the system scripts, the version 3.6 will replace Python 2.7 (more details here),
- about LDAP, OpenLDAP is no longer available, you have to use the 389 LDAP server or something else,
- you can’t remove NetworkManager from your configuration (it was already the case with the Gnome graphical environment in RHEL 7.5),
- KDE is removed from the desktop (KDE is deprecated according to the RHEL 7.6 release notes),
- a new mechanism called application stream is introduced (more details are available here, here and here).