Availability has traditionally been one of the most important aspects when providing services. When providing services on a shared platform like VMware vSphere, the impact of
downtime exponentially grows as many services run on a single physical machine.
As such VMware engineered a feature called VMware vSphere High Availability. VMware vSphere High Availability, hereafter simply referred to as HA, provides a simple and cost effective
solution to increase availability for any application running in a virtual machine regardless of its operating system.
It is configured using a couple of simple steps through vCenter Server (vCenter) and as such provides a uniform and simple interface. HA enables you to create a cluster out of multiple ESXi hosts. This will allow you to protect virtual machines and their workloads. In the event of a failure of one of the hosts in the cluster, impacted virtual machines are automatically restarted on other ESXi hosts within that same VMware vSphere Cluster (cluster).