Upgrading Red Hat OpenShift isn’t just about running oc adm upgrade.

Behind the scenes, a carefully orchestrated process ensures your cluster stays available while everything gets updated.

In this guide, I’ll walk through:

Real Upgrade path 4.19 to 4.20

Handling AdminAckRequired blockers

Setting upgrade channels properly

Understanding how OpenShift upgrades nodes (masters + workers)

Why Pod Disruption Budgets (PDBs) can make or break your upgrade

Pre-Upgrade :

Check that none of the operators are "Degraded"

Check PDB's.

Check Failing Pods.

Run a must gather (oc adm must-gather).

1.…