I have a little question.
Is it possible to monitor hardware failures on the esxi hosts?
For example when a disk is dead?
You would likely have to use a syslog analysis tool. We use Hyperic and the new better option we have is log insight. very solid and easy to setup and get value from.
If the health service in vCenter can detect the hardware failure, it'll be collected by and reflected as a "Fault" in vCOps. Just like if a NIC died and reported to vCenter as down/failed.