how upgrade Fedora 20 to 21

Friday, 1 August 2014

Hi, 
I have 2 machines that I use for tests , I'd like to update them from
Fedora 20 to Fedora 21. 

Where is the boot.iso or dvd.iso for Fedora 21, 
fedup is supposed to work ? 
using yum how I tell to yum that rpmfusion rawhide is relversion 21 ? 

Thanks, 
-- 
Sérgio M. B.