How to upgrade from CentOS 7 to AlmaLinux 8

Question

What are the steps involved in upgrading from CentOS 7 to AlmaLinux 8, and what are some best practices to ensure a successful upgrade?

Answer 1

Here are the steps involved in upgrading from CentOS 7 to AlmaLinux 8:

1. Back up your data: Before proceeding with the upgrade, it is important to back up all your important data to ensure that it is not lost in the event of an error during the upgrade process.

2. Install the AlmaLinux 8 repository: To upgrade to AlmaLinux 8, you need to add the AlmaLinux 8 repository to your CentOS 7 system. You can do this by running the following command:

   sudo rpm -Uvh https://repo.almalinux.org/almalinux/8.4-beta/BaseOS/x86_64/os/Packages/a/almalinux-release-8.4-2.el8.x86_64.rpm

3. Disable CentOS 7 repositories: To prevent any conflicts during the upgrade process, you need to disable the CentOS 7 repositories. You can do this by editing the "/etc/yum.repos.d/CentOS-*.repo" files and setting the "enabled" parameter to 0.

4. Perform a system update: Before upgrading to AlmaLinux 8, it is recommended to perform a system update using the command "sudo yum update". This will ensure that all packages on the system are up to date.

5. Install the AlmaLinux 8 packages: Once the system update is complete, you can proceed with installing the AlmaLinux 8 packages using the command "sudo yum swap centos-linux-release --replace-with=almalinux-release". This will replace the CentOS 7 packages with the corresponding AlmaLinux 8 packages.

6. Upgrade the system: Finally, you can upgrade the system to AlmaLinux 8 using the command "sudo dnf distro-sync". This will update all packages on the system to their corresponding AlmaLinux 8 versions.

Some best practices to ensure a successful upgrade include:

1. Back up all your data before proceeding with the upgrade.

2. Make sure that your system meets the minimum requirements for AlmaLinux 8.

3. Test the upgrade on a non-production system first to ensure that it works as expected.

4. Follow the upgrade instructions carefully and make sure that all steps are completed successfully.

5. Verify that all your applications and services are functioning properly after the upgrade.

6. Monitor the system closely after the upgrade to ensure that there are no unexpected issues or errors.

By following these best practices, you can minimize the risk of errors and ensure a successful upgrade to AlmaLinux 8.