As of my last update, there is no direct in-place upgrade path from Red Hat Enterprise Linux 8 to Red Hat Enterprise Linux 9. Red Hat typically releases new major versions of their operating system every 3-4 years, and each version is supported for a period of 10 years.
When upgrading between major versions of Red Hat Enterprise Linux, the recommended approach is to perform a fresh installation of the new version and then migrate your data and configurations over to the new system. This ensures a clean and stable environment for your applications and services.
Before proceeding with an upgrade, it's important to review the Red Hat Enterprise Linux documentation for any specific considerations or requirements for the migration process. Additionally, make sure to backup your data and configurations to avoid any potential loss during the upgrade process.
I would recommend checking the official Red Hat documentation or consulting with Red Hat support for the most up-to-date information and guidance on upgrading from RHEL 8 to RHEL 9.