Hi Eshwar,Greeting to you !!PM 21.2.12 on RHEL 8.4 may work but didn't test them so can't guarantee it, We tested RHEL 8.1 officially,https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/performance-management/22-2/installing/review-installation-requirements-and-considerations.htmlMost important part of the inplace OS upgrades is backups, If something goes wrong at least we have those to use in restoration.https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/performance-management/22-2/upgrading/plan-the-upgrade-or-migration.htmlHope this information helps, however anyone who tested may respond on this soon.Thanks & Regards,Mahesh Raj Thakur.