How to Switch From CentOS 8 to CentOS Stream
Edit: Please check out Anthony Geoghegan's answer for the latest recommendations.
This should work as CentOS Stream is just additional repositories on top of CentOS 8 as mentioned on (unofficial) centosfaq.org.
I did this on my development machine:
$ dnf history centos-release-stream
ID | Command line | Date and time | Action(s) | Altered
-------------------------------------------------------------------------------
156 | update --allowerasing | 2020-03-27 14:10 | E, I, U | 127 <
154 | install -y centos-releas | 2020-03-27 14:04 | Install | 1 >
Which resulted in the following enabled repositories
$ dnf repolist enabled | grep CentOS
AppStream CentOS-8 - AppStream
BaseOS CentOS-8 - Base
PowerTools CentOS-8 - PowerTools
Stream-AppStream CentOS-Stream - AppStream
Stream-BaseOS CentOS-Stream - Base
Stream-extras CentOS-Stream - Extras
centosplus CentOS-8 - Plus
extras CentOS-8 - Extras
fasttrack CentOS-8 - fasttrack
I needed to get rid of some manually compiled packages (--allowerasing) though. I would not do this on a production server or without a functioning backup.
After, it was announced that CentOS 8 would no longer be supported (end-of-life on 31 December 2021), upgrading to CentOS Stream became the officially recommended path to continue to receive software updates (RPMs).
Here are the notes I made while following the instructions for Converting from CentOS Linux to CentOS Stream:
1. Install the CentOS-Stream release files.
dnf install centos-release-stream
This package installs the following files:
/etc/dnf/vars/stream
/etc/yum.repos.d/CentOS-Stream-AppStream.repo
/etc/yum.repos.d/CentOS-Stream-Base.repo
/etc/yum.repos.d/CentOS-Stream-Debuginfo.repo
/etc/yum.repos.d/CentOS-Stream-Extras.repo
/etc/yum.repos.d/CentOS-Stream-Media.repo
/etc/yum.repos.d/CentOS-Stream-PowerTools.repo
/etc/yum.repos.d/CentOS-Stream-Sources.repo
/etc/yum.repos.d/CentOS-Stream-Vault.repo
/etc/yum.repos.d/CentOS-Stream-centosplus.repo
2. Replace the centos-linux repositories with centos-stream repositories:
dnf swap centos-{linux,stream}-repos
This replaces the following packages:
centos-release-stream
centos-release
centos-repos
with
centos-stream-repos
centos-stream-release
3. Update all packages to match the latest version available from all enabled repositories
sudo dnf distro-sync
For me, this installed a large number of packages, removed older kernel packages and downgraded the following packages:
httpd-2.4.37-30.module_el8.3.0+462+ba287492.0.1.x86_64
httpd-filesystem-2.4.37-30.module_el8.3.0+462+ba287492.0.1.noarch
httpd-tools-2.4.37-30.module_el8.3.0+462+ba287492.0.1.x86_64
However, it failed while attempting to upgrade the filesystem package and further attempts to run dnf update failed due to:
Error unpacking rpm package filesystem-3.8-4.el8.x86_64
This was because I had a filesystem mounted on /mnt. Unmounting this allowed the filesystem package to be upgraded and allowed the operation to complete successfully:
$ cat /etc/centos-release
CentOS Stream release 8
Note: I’ve only converted my own workstation to CentOS Stream. I have yet to replicate this procedure on a production server. :)