So, I attempted an upgrade to vCenter 6.5 again today and so far it is working. Wanna let it run for a couple days before I get excited!
I changed the following when I did the upgrade this time:
1) Unregistered VM with USB device before upgrading
2) Removed IPv6 address from vCSA 6 before upgrading
3) Completely disabled HA/DRS
I've also rebooted the upgraded vCSA a few times and it has been fine so far but still want to give it a couple days before upgrading my hosts. Veeam is happy too so backups are working (moved to ReFS for backup repository, damn its fast!)
The only odd thing I have noticed so far is (and maybe this is a GUI bug), here is my HA settings on the cluster in the HTML5 client:
Looks good right? Now check it out in the Flash client:
Is this a bug in the Flash client maybe?
One other thing I have noticed which is odd, when I set an IPv6 address again in the vCSA 6 appliance it loses it after a reboot?
Also, I don't have an option to upgrade my VMs VMware Tools. Normally after an upgrade if you right click a VM you get the option to update the tools but mine keeps saying I am up to date even though I know for sure I am two versions behind. Will this option come after updating my hosts maybe?