How to Migrate from CentOS 8 to Rocky Linux 8

Rocky Linux 8.4, codenamed Green Obsidian, is finally here! It was released on June 21, 2021, barely two months after the release of Rocky Linux 8.3 RC1 (Release Candidate 1) which is a beta version of the latest release.

This is the first stable and production-ready release of Rocky Linux after months of intense research and development. It is available for both x86_64 and ARM64 architectures. As you know by know, Rocky Linux is a community enterprise operating system that is 100% bug-for-bug compatible with Red Hat Enterprise Linux 8.4. This makes it a perfect alternative to CentOS 8 which will turn EOL by the end of December 2021.

With the release of Rocky Linux 8.4, a conversion tool has been made available to help you migrate from CentOS 8 to Rocky Linux. This is convenient for those who want to test out Rocky Linux 8 without performing a fresh installation.

Just to bring you up to speed, you can upgrade the following distributions to Rocky Linux 8.4:

  • Red Hat Enterprise Linux 8.4
  • CentOS Linux 8.4
  • AlmaLinux 8.4
  • Oracle Linux 8.4

Download Rocky Linux 8.4

If you want a fresh installation, proceed and Download Rocky Linux 8.4 which is available in minimal, DVD, and Boot ISO images.

Amazingly, Rocky Linux 8.4 is also available on Amazon Web Services (AWS Marketplace) and Google Cloud Platform. Additionally, you can find Rocky Linux in container images from the Docker Hub and Quay.io.

Migration from CentOS 8 to Rocky Linux 8.4

Before migrating to Rocky Linux 8.4, and any other operating system for that matter, It’s always recommended to back up all your files so that you can be on the right side of things should anything break.

To get started out, we’re are going to confirm the version of CentOS 8 that we are using for migration. We are currently running CentOS Linux 8.2 as indicated below.

$ cat /etc/redhat-release CentOS Linux release 8.2.2004 (Core)

You do not need to upgrade to the latest version of CentOS, as is the case when migrating to AlmaLinux 8.4 or Oracle Linux.

The next step is to download the migrate2rocky.sh migration script, which is hosted on GitHub and you can download it as follows using the wget command-line tool.

$ wget https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh
Download Rocky Linux Migration Script
Download Rocky Linux Migration Script

Once the download is complete, assign execute permissions to the migrate2rocky.sh shell script file as shown.

$ chmod +x migrate2rocky.sh

We are now all set to migrate to Rocky Linux.

To start the migration from CentOS 8 to Rocky Linux, execute the script as follows:

$ sudo bash migrate2rocky.sh -r
Migrate from CentOS 8 to Rocky Linux
Migrate from CentOS 8 to Rocky Linux

The script begins by identifying all the repositories that map from CentOS Linux 8 to Rocky Linux 8. It then removes CentOS 8 Linux packages & repositories and replaces them with their Rocky Linux 8.4 equivalents.

Removing CentOS 8 Repositories with Rocky Linux
Removing CentOS 8 Repositories with Rocky Linux

Next, it proceeds to download new packages required by Rocky Linux 8.4.

Downloading Packages from Rocky Linux Repo
Downloading Packages from Rocky Linux Repo

After downloading the packages, it reinstalls them and upgrades some of the existing packages to their latest versions. The entire migration takes quite some time, and in our case, it took roughly 3 hours. However, this is entirely dependent on your internet connection speeds. Also, the migration will take less time if you are running a minimal installation.

CentOS 8 to Rocky Linux Migration Process
CentOS 8 to Rocky Linux Migration Process

Once the migration is complete, you will be prompted to reboot your system as shown.

To reboot, run the command:

$ sudo reboot
CentOS 8 to Rocky Linux Migration Completes
CentOS 8 to Rocky Linux Migration Completes

During the reboot process, the Rocky Linux logo will be flashed – for the GUI installation.

Booting Rocky Linux
Booting Rocky Linux

On the Grub menu, be sure to select the ‘Rocky Linux‘ entry which appears as the first option.

Select Rocky Linux
Select Rocky Linux

Thereafter, log in with your user account credentials.

Rocky Linux Login
Rocky Linux Login

And this ushers to the dark-gray Rocky Linux desktop background.

Rocky Linux Desktop
Rocky Linux Desktop

And that’s it. You can now enjoy the stability and all the other goodies that Rocky Linux provides at absolutely no cost, just like you did with CentOS Linux.

Posted by Contributor