In connection with the upcoming termination of the CentOS distribution in its previous form and the transformation of CentOS into a testing ground for the development of Red Hat Enterprise Linux, Oracle invited CentOS 8 users to go to Oracle Linux and prepared script for migrating already installed systems.
The script automatically replaces CentOS-specific packages with equivalents from the Oracle Linux distribution. Migration from CentOS 6, 7, and 8 is supported. For CentOS 6, the transition is relevant due to the fact that the standard support for this branch of RHEL and CentOS has already been discontinued, and support for Oracle Linux 6 will last until March 2021.
Of limitations there is a lack of support for systems that use third-party centralized management tools such as Spacewalk, Foreman, and Uyuni.
The script only handles the main repositories, connecting external repositories, such as EPEL, must be done by the user separately. Compatibility with packages from external repositories is suggested but not guaranteed.
Oracle emphasized that it is unrestricted publishes Oracle Linux installation iso images and provides unlimited and free access to yum repository with package updates including bug fixes (errata) and security issues. Access to package code, binary assemblies, updates and patches is provided free of charge for any type of use, including enterprise use. You may redistribute packages and assemblies without signing any agreements with Oracle and without removing the Oracle trademarks from third-party supplies.
Oracle builds are published more quickly than CentOS – for RHEL interim releases, the Oracle Linux version is published within 5 business days (but usually in 24 hours). The Oracle distribution is 100% compatible with RHEL and allows you to use both standard packages with a kernel from RHEL, and your own Unbreakable Enterprise Kernel, including additional optimizations and features. Unlike packages with the RHEL core, all changes to the Unbreakable Enterprise Kernel are published in Git repositories with division into separate patches and detail list of changes.
Recall that Red Hat has limited the time of support for the classic distribution of CentOS 8 – updates for this branch will be released until December 2021, and not until 2029, as originally intended. CentOS will be replaced by the CentOS Stream build. The key difference between the new build is that the classic CentOS acted as a “downstream”, i.e. was going to already formed stable RHEL releases, while CentOS Stream is positioned as “upstream” for RHEL, i.e. it will test packages before being included in RHEL releases.