Converting your CentOS 8 to AlmaLinux 8 is pretty easy with conversion script. This opensource script supports the following operating systems and control panels: CentOS 8, Oracle Linux 8, RHEL 8, Rocky Linux 8 and control panels such as DirectAdmin, cPanel, and Plesk. The overall conversion can be simple in several steps.
Attention! Backup first!
Before attempting to convert a CentOS 8 system to AlmaLinux 8, users should be aware of the differences between the two distributions and the potential risks involved. It is also important to back up any important data before beginning the conversion process. AlmaLinux 8 has system requirements that are different from CentOS 8, so it is important to ensure that the system being converted meets these requirements.
Starting the conversion
In order to migrate from CentOS 8 to AlmaLinux 8, there are several steps that need to be taken. The system needs to meet the system requirements for AlmaLinux 8. Then, the actual conversion process can begin, which involves uninstalling the existing CentOS packages, installing the AlmaLinux packages, and configuring the system accordingly.
Login to the server with your favourite SSH client.
1. Apply pending updates to CentOS 8 by running the dnf command / yum command:
dnf update
2. Restart the server after the applying updates:
reboot
3. Download the almalinux-deploy.sh script by wget or curl command, type:
wget https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh
4. Now set the executable permissions using the chmod command:
chmod -v +x almalinux-deploy.sh
You will see the results:
mode of 'almalinux-deploy.sh' changed from 0644 (rw-r--r--) to 0755 (rwxr-xr-x)
5. Start migrating from CentOS to AlmaLinux by running the almalinux-deploy.sh:
./almalinux-deploy.sh
Be aware of the official CentOS 8 mirror lists changes. They are offline from January 31, 2022. In order to successfully perform dnf update -y you need to update your dnf config files to point to a valid mirror. If you get any error, do pass the -f as follows:
./almalinux-deploy.sh -f
6. Upgrading and migrating a system can take some time, as it is dependent on the server hardware specifications and server connection speed. Be patient and watch for any errors that may appear on screen. If the process is successful, a confirmation message should be displayed, such as: “Upgrade/migration successful. System is now running AlmaLinux 8.”
Complete! Run dnf distro-sync -y OK Restoring of alternatives is done OK Generating grub configuration file ... done All Secure Boot related packages which were not released by AlmaLinux are reinstalledOK Migration to AlmaLinux is completed
7. Great! Now it is upgraded. Reboot the machine:
shutdown -r now
Connection to 192.168.1.29 closed by remote host.
8. Login to the server again and verify the AlmaLinux version by command:
cat /etc/os-release
You will see the updated OS information:
[root@server ~]# cat /etc/os-release NAME="AlmaLinux" VERSION="8.7 (Stone Smilodon)" ID="almalinux" ID_LIKE="rhel centos fedora" VERSION_ID="8.7" PLATFORM_ID="platform:el8" PRETTY_NAME="AlmaLinux 8.7 (Stone Smilodon)" ANSI_COLOR="0;34" LOGO="fedora-logo-icon" CPE_NAME="cpe:/o:almalinux:almalinux:8::baseos" HOME_URL="https://almalinux.org/" DOCUMENTATION_URL="https://wiki.almalinux.org/" BUG_REPORT_URL="https://bugs.almalinux.org/" ALMALINUX_MANTISBT_PROJECT="AlmaLinux-8" ALMALINUX_MANTISBT_PROJECT_VERSION="8.7" REDHAT_SUPPORT_PRODUCT="AlmaLinux" REDHAT_SUPPORT_PRODUCT_VERSION="8.7"