As we all know, CentOS 8 had reached its EOL on the 31st of December 2021. Now CentOS is itself moving from being downstream to RHEL release to an upstream development branch of RHEL.

Upstream vs downstream

CentOS Linux is a rebuild of Red Hat Enterprise Linux (RHEL). As such, it is downsteam from RHEL. CentOS Linux release version numbers reflect the date of the RHEL release on which they are based.

CentOS Stream, on the other hand, is the upstream, public development branch for RHEL. Specifically, CentOS Stream 8 is the upstream for the next minor release of RHEL 8, CentOS Stream 9 for the next minor release of RHEL 9, and so on.

Upgrading from CentOS 8 to CentOS 8 stream

Please refer to our complete step by step guide on how to upgrade from CentOS 8 to CentOS 8 Stream.

Downgrading from CentOS 8 stream to CentOS 8

As mentioned above, CentOS 8 stream is the upstream for the next minor release of RHEL 8. So, what if there is something that you need as a mandatory feature, which is missing in CentOS 8 Stream and don’t find it?

Follow these steps to downgrade from CentOS 8 stream to CentOS 8.

1. Check the current version of CentOS

sudo cat /etc/os-release

2. Remove the centos-stream package

sudo dnf remove centos-stream-release

You will recieve a message like “Problem: The operation would result in removing the following protected packages: setup”

So take a backup of your current yum setup and re-run the command

sudo dnf remove centos-stream-release

3. Copy the repository files from a new CentOS 8 installation to /etc/yum.repos.d/ . You can download it from here.

4. Resync the CentOS 8 distro

sudo dnf distro-sync --releasever 8

5. Finally reboot the server

reboot

6. Welcome back to CentOS 8. Check the current version of CentOS

sudo cat /etc/os-release

And you are moved back to CentOS 8

Migrating CentOS 8 to CentOS 8 Stream is surprisingly as easy as maybe updating to the next version of CentOS itself!

First things first… Update the current system to the latest version of all the software packages. This ensures that firstly your yum repository cache itself is up to date and also updates the packages to the latest
sudo yum -y update

Now lets install dnf – DNF is the software package manager that installs, updates, and removes packages and is a successor to yum
sudo yum -y install dnf

Just to know that we are indeed on CentOS 8 before begining the migration, check the current version of CentOS
sudo cat /etc/centosos-release

Disable current CentOS 8 linux repository and replace them with their corresponding CentOS 8 Stream ones
sudo dnf --disablerepo '*' --enablerepo extras swap centos-linux-repos centos-stream-repos

sudo sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*

sudo sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*

Its time to synchronize the latest distributions of all the software packages meant for CentOS 8 Stream
sudo dnf distro-sync

Finally, reboot the system
sudo reboot

Moment of truth. Once the server is back online after the reboot, check the OS version post the upgrade
sudo cat /etc/centos-release

That’s it!