How to convert from CentOS 8 to AlmaLinux 8

Introduction

CentOS 8 and other EL8 servers can be converted to use CloudLinux's fork of RHEL, AlmaLinux. CentOS 8 is currently slated for End-of-Life status on December 31, 2021.

Note: This procedure is currently in beta status, and should not be run on production servers. Full backups are highly suggested prior to performing these steps.

Procedure

Download the almalinux-deploy script:

# curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh

Run the script:

# bash almalinux-deploy.sh

Wait for the process to complete, check for errors:

Complete!
Run dnf distro-sync -y OK
Restoring of alternatives is done OK
Generating grub configuration file ...
done
All Secure Boot related packages which were released by not AlmaLinux are reinstalled OK

Migration to AlmaLinux is completed

Verify that the installation is complete:

Check release file

$ cat /etc/redhat-release 
AlmaLinux release 8.4 (Electric Cheetah)

Check that the system boots AlmaLinux kernel by default

$ sudo grubby --info DEFAULT | grep AlmaLinux
title="AlmaLinux (4.18.0-305.el8.x86_64) 8.4"

More information about the conversion script is available in the AlmaLinux GitHub here:

almalinux-deploy