@laszlobortel While I can understand "Upgrading not being an option" you're lift and shifting the workload (or at least have been attempting to do this to date).
Are you unable to build new and migrate data over to XCP-ng, while I could see this causing more work, lift and shifting is almost always a guaranteed way to cause headaches - like the ones you're experiencing.
That is why each service provider recommends building new if you can. At the same time that you're building new, you're updating which of course can cause issues - but continuing to run Rocky8 is only receiving security updates until 2029. Sure it has a few years left, but why not take the opportunity to upgrade?
They can possibly go up to Rocky 9 but Rocky 10 later may be harder, as it requires a higher baseline on the CPU. Also they may have legacy software that only works on Rocky 8.


