CentOS - convert alma9 / rocky9 to c9s

So with the recent announcement from redhat (I won't take any sides here) regarding their sources and where they're being published to, I decided to check how easy a conversion of any current el9 release to centos9-stream was, I also only found conversions the other way round (centos-stream -> alma / rocky).

Now, I will personally stay on a downstream-distro for as long as I can due to compatibility reasons.

Anyway, here are the steps required to convert your existing alma9 / rocky9 installation to a centos9-stream installation. First, download the release, repos and gpg-keys packages:

 [root@server ~]# curl -4kLOX GET 'https://ftp.sh.cvut.cz/centos-stream/9-stream/BaseOS/x86_64/os/Packages/centos-stream-release-9.0-21.el9.noarch.rpm'  
 [root@server ~]# curl -4kLOX GET 'https://ftp.sh.cvut.cz/centos-stream/9-stream/BaseOS/x86_64/os/Packages/centos-stream-repos-9.0-21.el9.noarch.rpm'  
 [root@server ~]# curl -4kLOX GET 'https://ftp.sh.cvut.cz/centos-stream/9-stream/BaseOS/x86_64/os/Packages/centos-gpg-keys-9.0-21.el9.noarch.rpm'

Next, initially install the 'centos-stream-repos' and 'centos-gpg-keys' rpms:

 [root@server ~]# dnf -4y install centos-stream-repos-9.0-21.el9.noarch.rpm centos-gpg-keys-9.0-21.el9.noarch.rpm

Now that the requirements have been met for the 'centos-stream-release' package, swap the almalinux-release / rockylinux-release package with the one from centos-stream:

 [root@server ~]# dnf -4y --refresh swap almalinux-release centos-stream-release-9.0-21.el9.noarch.rpm

Run a final distro-sync to install / upgrade / downgrade any necessary packages and reboot the system to ensure it's in a consistent state:

 [root@server ~]# dnf -4y --refresh distro-sync  
 [root@server ~]# systemctl reboot

After the host is reachable again, confirm the conversion has worked:

 [root@server ~]# cat /etc/os-release   
 NAME="CentOS Stream"  
 VERSION="9"  
 ID="centos"  
 ID_LIKE="rhel fedora"  
 VERSION_ID="9"  
 PLATFORM_ID="platform:el9"  
 PRETTY_NAME="CentOS Stream 9"  
 ANSI_COLOR="0;31"  
 LOGO="fedora-logo-icon"  
 CPE_NAME="cpe:/o:centos:centos:9"  
 HOME_URL="https://centos.org/"  
 BUG_REPORT_URL="https://bugzilla.redhat.com/"  
 REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux 9"  
 REDHAT_SUPPORT_PRODUCT_VERSION="CentOS Stream"

Okay, so the installation is now converted from almalinux to centos stream and should work just as before.

Feel free to comment and / or suggest a topic.

Comments

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