It may sound a bit strange, BIOS settings causing HA problems…… At the client site were I previously had problems with faulty HP USB sticks I still experience problems. After the problems with the green USBs after 1,5 week we received new black USBs. This seemed to solve our problems, we swapped all USBs, configured all ESXi hosts and build a new cluster and enabled HA. All seemed well untill I updated all hosts with all the latest patches. After applying the updates one of the hosts failed to re-enable HA. I checked everything like configuration, DNS, hosts file, FT_HOST file, logs but I could determine the cause of this problem. A collegue, who was connected to iLO, noticed that this host booted a lot slower so we decided to check the BIOS settings. All settings were 100% identical except the USB 2.0 controller was disabled at the troubled ESX host. After we enabled the USB 2.0 controller the host booted a lot faster and after 10 minutes we managed to enable HA without any problems.

So, you tell me did the BIOS setting cause HA to fail? Everything points in that direction. I asked our VMware Partner SE if this could have caused our problems but no news so far. When I hear from him you all will be the first to know.