How to make an in-place upgrade of a Plesk server from CentOS 7 to AlmaLinux 8?

Question

CentOS 7 reaches end-of-life on June 30, 2024. Does Plesk support an in-place upgrade from Centos 7 to AlmaLinux 8?
How such a conversion can be done?

Answer

We prepared a CLI script that in-place converts a Plesk server with CentOS 7 to AlmaLinux 8.

Warning: Plesk services, hosted websites, and emails will be unavailable during the conversion process for about 30 to 60 minutes. Server is going to be rebooted, conversion automatically progresses after reboot.

1. Create a server-wide backup in Plesk and/or create a server snapshot in advance, so it can be used as a recovery point in case the convention process fails.

2. Ensure that you have a way to restart the server without a direct SSH connection. A serial port connection to the server can be used to monitor the status of the conversion process in real time and to reboot the server if necessary.

3. Connect to the server via SSH.

4. Verify there are at least 5GB of free space on disk.

5. Warning: Verify and disable custom repositories configured on the server. These repositories are known to cause issues due to potential scale of replacement of base packages. They are configured on /etc/yum.repos.d folder.

   1. Examples of repositories that should be enabled or disabled (via yum repolist enabled):

      ❌Repositories that should be disabled:

      • city-fan.org
      • CentOS Plus
      • Remi Repository
      • RPMFusion
      • ELRepo
      • Software Collections (SCL)
      • IUS Community Repository

      ✅CentOS official repositories

      • base/7/x86_64
      • extras/7/x86_64
      • updates/7/x86_64

      ✅Repositories added by Plesk

      • epel/x86_64
      • PLESK_17_PHP
      • PLESK_18_0_66-extras
      • imunify360
      • imunify360-rollout

6. Download and prepare the script:

   # wget https://github.com/plesk/centos2alma/releases/download/v1.4.5/centos2alma-1.4.5.zip

   # unzip centos2alma-1.4.5.zip

   # chmod 755 centos2alma

7. Run the script:

   # ./centos2alma

   • Perl modules installed via CPAN are not supported. To forcefully remove them during the conversion, append the '--remove-unknown-perl-modules' flag:

     # ./centos2alma --remove-unknown-perl-modules

   • If PostgreSQL version <10 is installed, is recommended to upgrade it prior to starting conversion. Alternatively, use the --upgrade-postgres flag to upgrade PostgreSQL during the conversion:

     # ./centos2alma --upgrade-postgres

   Note: flags can be combined if both of the above is the case:

   # ./centos2alma --upgrade-postgres --remove-unknown-perl-modules