During an in-place operating system (OS) upgrade, the existing Oracle E-Business Suite environment is preserved on your current hardware while the existing operating system is upgraded to a newer version. I am pleased to announce that an in-place OS upgrade from Oracle Linux 7 to 8 using the Leapp utility is now certified for Oracle E-Business Suite 12.2. 
The Leapp utility provides a framework to upgrade the operating system in coordination with existing applications. Leapp can be used to upgrade on-premises environments and Oracle Cloud Infrastructure (OCI) compute instances. The Leapp utility produces a pre-upgrade report that outlines details of issues, as well as possible required remediations before proceeding with the OS upgrade.
You should review the Leapp documentation for prerequisite requirements, restrictions, and instructions on running the following phases of the utility to perform the in-place upgrade of Oracle Linux 7 to 8:
- pre-upgrade
- analysis/resolution of issues
- upgrade
- post-upgrade tasks
References
- Oracle E-Business Suite Installation and Upgrade Notes Release 12 (12.2) for Linux x86-64 (MOS Note 1330701.1)
- Upgrade Oracle Linux with Leapp