I have 2 host in my environment one being considerably more powerful then the other 40Core/160GB MEM vs 16Core/64GB MEM. Which I will be upgrading both to run esxi 6.5u2 since that's what the older one is limited to by compatibility. I have a few virtual machines (3 Really Exchange,1 Accounting VM, and PFsense Router) that I want to provide some fault tolerance for. Since there is such a resource gap between the two I was wondering does the second VM thats setup for fault tolerance consume any resources while its not being used? I do have a few VM's running 16core one that I would shutdown if a failure was to happen on the 40core. What's the best way to configure this is HA the right direction or is there a better solution?
Yes, the active and passive VM within a Fault-Tolerance protected VM consumes resources.
How many resources are allocated in your environment overall (vCPUs / Memory)?