If I understand"
When they say ESX boots from SAN… it means the ESX Operating System is installed on the SAN and the ESX physical box is diskless but provides RAM/CPU resources to ESX as well as to VMs.
in this case if ESX goes down , the VMs will still be rebooted on other ESX hosts considering VMHA is enabled? or another ESX host will take over without having the VMs reboot?
by the way , how much RAM/CPU an ESX server consumes for its own needs, without counting RAM/CPU that it provides for VMs.?