How to upgrade from AlmaLinux 8 to AlmaLinux 9

AlmaLinux is developed by the AlmaLinux OS Foundation established as a non-profit to steward ownership. The void created by the end of the CentOS Linux stable release is filled by AlmaLinux OS, an open-source, community-driven Linux operating system. AlmaLinux OS is a community-driven 1:1 binary compatible clone of RHEL®.

This tutorial walks readers through the process of upgrading AlmaLinux 8 to AlmaLinux 9.

NOTE: Always backup the server before you make major changes.

1. Update the server and make sure all software installed is up to date, running the latest release of AlmaLinux 8.

   
   

   Type in the following command in the console to update.

   # yum update -y
   

   

2. After the update is completed, reboot the server.

   # reboot
   

   

3. Once the server has been restarted, verify that it is running the latest AlmaLinux release.

   # cat /etc/os-release
   

   

4. Downloading the elevate testing repository is the next step. Elevate aids in distributions based on the RHEL version migration. Run the next command to down the repository.

   # curl https://repo.almalinux.org/elevate/testing/elevate-testing.repo -o /etc/yum.repos.d/elevate-testing.repo
   

   

5. Confirm that the repository is added by running the following command.

   # ls /etc/yum.repos.d/ | grep elevate
   

   

6. Import the Elevate GPG key.

   # rpm --import https://repo.almalinux.org/elevate/RPM-GPG-KEY-ELevate
   

   

7. Disable SELinux.

   # vim /etc/sysconfig/selinux
   

   

8. Change SELinux mode to Disabled.

   SELINUX=disabled
   

   

   NOTE: Once the upgradation process is completed, change the SELinux option to enforcing.

9. Reboot after disabling SELinux.

   # reboot
   

   

   NOTE: If the SELinux is already disabled on the server, skip step 4.

10. Disable the firewalld ZoneDrifting feature.

    # vim /etc/firewalld/firewalld.conf
    

    

11. Disable Zonedrifting by changing yes to no.

    AllowZoneDrifting=no
    

    

12. Install leapp packages.

    # yum install -y leapp-upgrade leapp-data-almalinux
    

    

13. Run a pre-upgrade check.

    # leapp preupgrade
    

    

14. Upgrade AlmaLinux 8 to AlmaLinux 9 now.

    # leapp upgrade
    

    

15. Reboot after the upgrade.

    # reboot
    

    

16. Once rebooted, check the OS version.

    # cat /etc/os-release
    

    

The server has successfully upgraded from Almalinux 8 to Almalinux 9.