How to migrate from CentOS to AlmaLinux

In order to upgrade to AlmaLinux, you need to access your VPS via SSH. All the commands should be executed in CLI. The upgrade process will take less than 15 minutes. Please execute commands from this guide one by one (don’t copy the $ symbol). Please make sure that the previous command has succeeded before executing the next one.

The full video guide can be found at the end of this instruction.

Preparation

1. Make a backup of all important files before upgrading. If you need help, contact our support team – we’ll make a backup for you.
2. Before updating CentOS 8 to AlmaLinux, you need to check that your CentOS 8 version complies with updating requirements. Please run the following command:

   $ cat /etc/centos-release​

   1. If your version is 8.3 or higher, please proceed directly to the “Upgrading to AlmaLinux” step.
   2. If your version is 8.2 or lower, update your system packages by running the following command:

      $ dnf update​

      Wait until the system loads the packages list and asks for confirmation. Then confirm the update by typing “y”:

      Transaction Summary
      ==========================
      Install 22 Packages
      Upgrade 284 Packages
      
      Total download size: 377 M
      Is this ok [y/N]:​ y

      Wait until the system installs all updates. Then run the check OS version command again

      $cat /etc/centos-release​

      Make sure that your OS version is 8.3 or higher now and reboot your VPS after the system update.

Upgrading to AlmaLinux

1. Download the almalinux-deploy.sh script:

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

2. Run the OS upgrade:

   $ sudo bash almalinux-deploy.sh​

   Wait until you see this message: “Migration to AlmaLinux is completed”

3. Check the current OS version:

   $ cat /etc/redhat-release​

   The output should look like this: AlmaLinux release 8.4 (Electric Cheetah)

4. Check that the system boots AlmaLinux kernel by default:

   $ sudo grubby --info DEFAULT | grep AlmaLinux​

   The output should look like this: title=”AlmaLinux (4.18.0-305.el8.x86_64) 8.4″

Done! You are awesome.