Migrate CentOS 8 to Oracle Linux Using the Official centos2ol.sh Script

Oracle Linux is a binary‑compatible alternative to CentOS 8, built from Red Hat Enterprise Linux sources and offered with two kernels: the default RHEL‑based kernel and Oracle's Unbreakable Enterprise Kernel (UEK) optimized for performance and stability.

Prerequisites and Environment Check

Start from a CentOS 8 Minimal installation. Verify the OS version and kernel:

[root@localhost ~]# cat /etc/os-release
NAME="CentOS Linux"
VERSION="8 (Core)"
...

[root@localhost ~]# uname -r
4.18.0-240.15.1.el8_3.x86_64

Download and Prepare the Migration Script

The Oracle GitHub repository provides centos2ol.sh, which supports migration from CentOS 6, 7, 8 (but not CentOS Stream). Retrieve it with wget or curl and make it executable:

wget https://raw.githubusercontent.com/oracle/centos2ol/main/centos2ol.sh
chmod +x centos2ol.sh

Run the Migration

Execute the script to start the automated conversion of installed packages to their Oracle Linux equivalents and to install the appropriate kernel: ./centos2ol.sh The script lists the packages it will replace and then performs the changes.

Reboot and Verify

Reboot the system. The GRUB menu now shows two entries for Oracle Linux Server: one for the standard kernel and one for UEK. [root@localhost ~]# reboot After boot, confirm the new OS release and kernel:

cat /etc/os-release
NAME="Oracle Linux Server"
VERSION="8.4"
...
uname -r
5.4.17-2102.202.5.el8uek.x86_64

Conclusion

The CentOS 8 system is now fully migrated to Oracle Linux Server with the UEK kernel, providing a stable, supported alternative to CentOS.