I have the same issue... sort of... I'm running a pidrive and put an image on it... worked beautifully... I started adding more roms... then got to a point where it told me I didn't have any more room... I have a terabyte tho... I tried expanding the file system and says sda2 is not an sd card... it won't let me... So i'm in the same boat as you... I saw noobs is an option but I have not tried it... I'm not sure if it will mess with my image or not...