Development of any technology requires ideas, which need a lot of testing, before then can actually work. The problem is that testing and POC typically happen before the idea can make any money, relying heavily on free and open-source solutions.
There is no decent free SMB3 fileserver. Those available are critically unreliable or just aren’t working properly. In case you need one right now and there is no other way of acquiring it, there is a way – the Free Microsoft Hyper-V Server 2012R2. However this method violates license agreement, so it’s not in any way a permanent solution for your problems. You may take the risk and try it once in order to see if your idea works, but we still strongly discourage you from repeating this experiment.
In any case, let’s see if you can build an SMB3 fileserver on Free Microsoft Hyper-V Server 2012R2 and if it works, go further and see if we can create a failover fileserver. Check out the following posts and see: