A bit of background before I get into my main question: Without a second mac hat was compatible I was running the Yosemite beta on a second partition of my internal HDD. It installed and ran perfectly fine. However with the OS officially released I deleted the partition in order to upgrade my mac in full. Now, however, I cant re-size my boot partition (Macintosh HD) in order to fill up the space that Yosemite was taking up. I can pull the corner in Disk utility and it doesnt give me an error when I hit apply but nothing appears to happen. Ive attached a screenshot of what it looks like. At first I assumed it was because I was running off the partition so I booted my iMac into the recovery partition and tried in there. However when I pulled the partition out and hit apply I received an error about not being able to unmount. I dont remember the exact wording now but it didnt work obviously. So, that brings me here. How do I get this unpartitioned space back to being my Macintosh HD partition? I would like to get this figured out before I install Yosemite so that my computer is fully back to normal in advance. Im sure I could clean install Yosemite and just start from scratch off a time machine backup but I would much rather not go that route.