When creating an availability set the default number of fault domains is 2. As an example you want to deploy 3 VM's, would you consider using 2 or 3 fault domains? As a requirement 1 VM must be online all the time.
My question: are there any considerations why you would choose 2 fault domains over 3 fault domains? I'm trying to understand why 2 fault domains is the default number, instead of 3? Is it network related, performance?
there is no reason to pick 2 instead of 3 as 3 is strictly better, but some regions only support 2 fault domains. so you'd have to go with 2 fault domains in those regions.