There are several features such as DRS (Distributed Resource Scheduler), SMP (Symmetric Multi-Processing), VMotion, etc., but why do we need ‘HA’?

There are several features such as DRS (Distributed Resource Scheduler

1.	There are several features such as DRS (Distributed Resource Scheduler), SMP (Symmetric Multi-Processing), VMotion, etc., but why do we need ‘HA’?
Answer» VMware HA is critical for us since we need uninterrupted service. Let's suppose that ONE of the ESX servers in the cluster crashes SUDDENLY for some reason. What would happen to the VIRTUAL machines running on that server? Do they CONTINUE running or are they falling? Likewise, they go down too. Thankfully, VMware HA allows you to RESTART these VM's on any other ESX server in the same cluster as soon as they fail.