HA planing resources doubt

[dariosaurio]

Hello everyone, I have some questions regarding VMware HA that I can't fully undestand

[dariosaurio]

When planning VMWare infraestructure, If I want a VM to work in HA, Do I have to reserve CPU, RAM, Storage ?? because if 1 vm is sleeping waiting for the master VM to fail, it's not ussing CPU, Am I correct?

[weinstein5]

Welcome to the Community - you are confusing two VMware products that provide High Availability - VMware HA and VMware FT -

VMware HA (High Availability)  - Allows you to respond in the event of a host or VM failure by RESTARTING the VM on an available host - the key word is restarting meaning there will be a brief outage

VMware FT  (Fault Tolerance) - Allows for the recovery of a VM in the event of a host or VM failure - in FT there is a VM tat is shadowing the primary VM and when that VM fails it will seamlessly take up the VM load with no downtime -

for most HA installations you do not have to set reservations of CPU. memory or storage -

[dariosaurio]

Haaa, that's why I could't undestand HA cuz I was thinking in Fault Tolerance :smileysilly:

[weinstein5]

and to add in FT the secondary VM is not sitting idle - it is not using as many resources as the primary VM but it is using some -