So I have an EC2 instance running RHEL 8.9 which was recently upgraded from RHEL 7.9. Now, I want to upgrade it all the way to RHEL 9. Here is the worklog which recording the steps I performed to achieve that goal. Step 0, perform a snapshot of the root volume of the instance, or create an AMI from it. In my case, this is just a test instance, so I skip taking the snapshot. ...
Well, if you know you know, otherwise, you could have wasted the whole evening trying to upgrade RHEL 7.9 with High Availability to RHEL 8.x, and failed! If you read this post, head to the link at [1] and you’d see that Red Hat does not support i-place upgrades or rolling-upgrades of cluster nodes from one major release of RHEL to another. Here is an extract from [1]: Red Hat does not support in-place upgrades or rolling-upgrades of cluster nodes from one major release of RHEL to another. For example, there is no supported method for updating some nodes in a cluster from RHEL 6 to RHEL 7, introducing them into the cluster with existing RHEL 6 nodes to take over resources from them, and then updating the remaining RHEL 6 nodes. Upgrades in major releases of RHEL must be done by migrating services from a running cluster on the old release to another cluster running the new release. ...