The fundamental principle of HA is to be able to recover virtual machines from a host that has failed to another. That implies that other hosts in the cluster are capable of providing compute, storage, and network identity for the virtual machine similar to the failed host.
vSphere HA is not enabled by default on a host cluster. It has to be manually enabled. In this recipe, we will understand the requirements of a HA cluster, how it is enabled, and how it works.