I'm just gonna pipe up since I saw your first post and I deliberately didn't answer. Your questions and comments are to the point that I think you need to consider an alternative solution. You don't appear to have the experience or knowledge to be able to safely store your data with FreeNAS. You are welcome to do what you want. I'm only giving you this warning because I've seen so many people think they have it all figured out, dump their life's data on the pool, think its all safe and all is great, then suddenly lose it all in an accident that was waiting to happen because of some error they didn't know they made during initial setup.
FreeNAS isn't for standard people that want a cool server. FreeNAS is for IT professional that have done this stuff for years. And even at that, I've seen so many IT professionals that got cocky and thought their 10+ years in the industry was enough to do this without a problem STILL lose data.
The reason I'm saying all of this is because it's clear you really don't know what you are getting yourself into. And I don't like seeing people lose their data.