Hello, I'm considering installing the El Captain public beta onto a secondary partition on my rMBP 2015 running 10.10.4. I have the base model with 128GB of storage (which is more then enough for my needs, as I store any large files I don't use regularly on an external 500GB hard drive that I also use as a Time Machine backup). Currently (according to the Finder) I have 62.29 GB of free space available on my computer. However when I go to create a secondary partition the largest it will let me make it is 42.79GB. Does Apple put a limit on to how large one can make a secondary partition? From what I've heard people recommend at least 30GB for running the beta software (which is what I'm planing to do, since I don't intend to use it as a primary OS) so basically I just want to make sure I'm not limiting the amount of storage available on my main partition by more then I think I am. Thanks.