I have a 2012 MBP, with a pre-formatted hard drive The partitioned hard drive says that it's got 125 free Gigs, but the start up disk says it has only 18.9 mb free. I can't figure out how to clear that extra info on the start up...and I assume it's a problem. I have been getting the beach ball and poor performance lately, and was about to increase the memory (from 8G to 16G), when I noticed this. I' ve rebooted in Recovery mode and repaired one or two problems but it's still there. screen grabs attached. thank you!!