Estimated volume size differs (quite a bit) from actual volume size, is this normal?

[Toxic Waste]

I was wondering if anyone can tell me it's normal that when you create a volume via the volume manager, the actual size is smaller than what the volume manager says it will be? Yesterday I got my first freenas install running, and I put in my 6 x 5 TB western digital, used RaidZ1 so I would have the one disk parity. And the volume manager told me this:

However, when I add the volume, it seems to be at least 1 TiB smaller than the estimated, is this normal? When I open the volumes I get this:

So basically it's 1.5 TiB below the estimated size, is this within the boundaries of normal or did I make a mistake somewhere?

Any feedback is greatly appreciated :)

 

[Yatti420]

That's fine and by GUI design i believe..

 

[Mlovelace]

So basically it's 1.5 TiB below the estimated size, is this within the boundaries of normal or did I make a mistake somewhere?

Any feedback is greatly appreciated :)

It's fine, the 1.5TiB went to padding for the RaidZ. Here is a write-up you might find interesting: http://blog.delphix.com/matt/2014/06/06/zfs-stripe-width/

 

[SweetAndLow]

It's fine. Have you read the book guide it will help you set up freenas correctly so you have a good experience.