This guide will help you to migrate in-place your current CentOS 8 installation to AlmaLinux 8 in a few simple steps.
As you know, CentOS 8 reached its End-of-Life on December 31, 2021. If you want to migrate your CentOS 8 server to AlmaLinux 8, a 1:1 binary compatible with CentOS and RHEL, follow the steps below.
An in-place upgrade involves using the official AlmaLinux automated script to migrate your current CentOS 8 operating system files to AlmaLinux.
In addition, an in-place upgrade does not require formatting of the hard disk, and due to that fact, all settings, programs, and files on your current CentOS 8 system will be preserved.
Steps to Migrate CentOS 8 to AlmaLinux 8
Here’s our CentOS 8 system before starting the migration process to AlmaLinux.
1. Take System Backup
Before upgrading, please make sure you take the backup of all your important data and, if possible, take a snapshot of the complete CentOS 8 system. This way, you will be on the right side of things if anything goes wrong.
2. Upgrade the Current CentOS 8 System
The next step in the upgrade process is to ensure we have a wholly upgraded system. Update existing software with the following command:
sudo dnf update
Once all the packages are updated, reboot your system to apply the changes.
Now let’s verify our current operating system version.
3. Download the Official AlmaLinux Migration Script
The first step in the actual upgrade process is to download the
almalinux-deploy.sh script from the AlmaLinux GitHub repo:
curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh
Next, make the script executable:
chmod +x almalinux-deploy.sh
3. Migrate from CentOS 8 to AlmaLinux 8
Finally, with the script available locally, run it to start the migration process:
sudo bash almalinux-deploy.sh
After the migration script performs a few initial checks, it will begin upgrading specific packages to synchronize the system with the current AlmaLinux 8 release.
Be patient since the upgrade process could take some time.
Once the migration is completed, you will get:
Run the following command to sync installed packages and then reboot the system:
sudo dnf distro-sync -y sudo reboot
The GRUB menu will appear with the AlmaLinux entry at the very top. Just hit
Enter or wait a sec, and it will boot automatically into AlmaLinux 8.
4. Check AlmaLinux Version to Validate Migration
To confirm that you have successfully migrated, check the OS version:
That’s all. Congratulations! You have successfully migrated from CentOS 8 to AlmaLinux 8.
(Optional) In addition, you can change the server hostname to match with AlmaLinux:
sudo hostnamectl set-hostname almalinux8 sudo reboot
Please note that the
almalinux-deploy.sh script will only convert CentOS 8 version to AlmaLinux 8. If you are running an older version like CentOS 7.x, all you have to do to switch to AlmaLinux 8 is follow our detailed guide – How to Migrate CentOS 7 to AlmaLinux 8: A Step-by-Step Guide.
I have tried to make this guide as simple as possible. Thanks for using it! Feel free to share your thoughts in the comments box below.