horizonbrave

Hello everybody I was fascinated by Synology HA (High Availabilty) feature. I know that one of the requirments is to have 2 identical (as in model, as in disks -size/number/order-, as in RAM) units. I wonder please: 1) is HA supported in XPEnology? 2) do the machines have be indentical and if not which are the requiremens? I only checked the forum FAQs and couldn't find any reference. Sorry if I missed a tutorial or something and thanks for suggestions or links