What is CentOS 8?¶
The CentOS Project is a community-driven free software effort focused on delivering a robust open source ecosystem around a Linux platform. Packages contained in CentOS are built from source code from the RedHat Enterprise Linux (RHEL) distribution. More information on the CentOS project can be found upstream at the CentOS website.
Change of end-of-life of CentOS 8¶
On the 8th of December 2020, the CentOS Project announced it was shifting its focus from CentOS to CentOS Stream, starting with the latest version, CentOS 8. Support for CentOS 8 will end at the end of 2021, and support for CentOS Stream 8 will continue until 2024. Prior to this announcement, CentOS 8 was slated to be supported until 2029.
What's the difference between CentOS and CentOS Stream?¶
Currently, CentOS is a rebuild of Red Hat Enterprise Linux (RHEL). In order to build RHEL, Red Hat engineers take a Fedora release, perform all their QA tests and assemble all the changes they want to make in their internal repositories. They rebuild all their packages and produce a new release of RHEL. Once this process is done, they push their sources to the CentOS public git repository. At this point, the CentOS project takes these source RPMs, rebuilds them and produces a new release of CentOS.
With CentOS Stream, Red Hat is doing their development work out in the open. They will continue to take Fedora releases and perform their QA on them, but now they will assemble all their changes publicly as CentOS Stream. Every 6 months or so, Red Hat will take CentOS Stream and rebuild it as a new RHEL point release. Once that is done, the sources of this new RHEL point release are rebuilt to produce a new CentOS release. This last step will now stop at the end of 2021.
CentOS Stream will be more up-to-date than RHEL, whereas CentOS has traditionally lagged behind.
Does this mean that CentOS Stream is RHEL's QA?¶
No, Red Hat will continue their internal QA workflow. CentOS Stream will get the updates that have passed that QA process.
Can a CentOS machine be upgraded to CentOS Stream¶
Yes, migrating from one to the other is simply a matter of changing the repositories you get your updates from.
Will we still have 10 years of support?¶
No, the major implication of this change is that support for major releases is shortend to 5 years. New major CentOS Stream releases should come out regularly with an overlap of 2-3 years, providing an upgrade path.
After 2024, CentOS Stream 8 will no longer be maintained. CentOS Stream 9 is estimated to be ready for production by 2022.
How is CERN going to adapt to this?¶
CERN acknowledges the recent decision to shift focus from CentOS Linux to CentOS Stream, and the sudden change of the end of life of the CentOS 8 release. This may entail significant consequences for the worldwide particle physics community. We are currently investigating together with Fermilab the best path forward. We will keep you informed about any developments in this area during Q1 2021.
- CentOS 8 @ CERN was initially introduced via an ASDF session on the 12.12.2019
- The operating system is supported by CERN IT as the next production linux distribution of CERN, as of April 2020. We strongly encourage all users of SLC6 and CC7 to migrate to C8.
How does CERN use CentOS 8?¶
CentOS 8 updates are staged
- A 'production' repository is provided, which most systems will use and is updated once per week (except for critical security vulnerability patches)
- A 'testing' repository is also provided which is updated daily
- Snapshots of CentOS repositories are performed daily and can be found at this URL
- The 'cern-yum-tool' is a new package that can be used to easily switch between 'production', 'testing' or 'snapshot' repositories
- The 'yum-autoupdate' package is provided for automatic (distro-sync) updates (the same as CC7).
- Yum repositories files changed to use http://linuxsoft.cern.ch/cern/centos/8/
- Added CERN Koji RPM signing keys
- Yum repositories files changed to use http://linuxsoft.cern.ch/
Note: Unless otherwise stated above, CentOS 8 packages (rpms) are the very same packages released by the upstream CentOS team.