We get more new cool feature if keep virtual hardware up to date. And you may face boot problem when upgrade lower virtual hardware version to latest.
I always keep my Microsoft Cluster Services VM (MSCS VM) up to date since RDM disk usually uses on that kind of VMs.
I tried to search how to upgrade virtual hardware on MSCS VM with RDM LUN, but no lucky. That's my experience:
- Update manager doesn't work for MSCS VM.
- No snapshot would be taken if your SCSI controller of RDM is physical mode, you should have a good backup before upgrading.
- It's possible to force upgrade hardware version by right click VM and select Upgrade Virtual Hardware.
- Make sure all services are running on another node.
- You will get following error message on Event for RDM disks in vSphere Client, upgrading procedure won't be finished until error pop out for all RDM disks.
- I tried upgrade version 7 to 8.