Problems with partitioning

eravulgaris

macrumors newbie
Original poster
Jun 13, 2013
6
0
Hi guys, I've got a (big?) problem. I wanted to format my entire harddisk (128GB SSD, probably doesn't matter) to install Mountain Lion on it. There was a bootcamp partition on it as well, which I erased. I did this in Disk Utility in recovery mode (when I pressed CMD + R in the beginning).



The problem is, I wanted to erase my whole HD so I could have it whole again, but I couldn't because it said something about: "unable to unmount partition".

So now I'm left with a BOOTCAMP partition and a greyed out part that I can't use. I've tried resizing the HD to take the gray part, but it doesn't work.

I've got no idea what to do...

Thanks in advance guys. These problems are hard to explain.
 

pnyc

macrumors 6502
May 12, 2007
264
0
Brooklyn, NY
Since you want to format the entire drive simply make a bootable Mountain Lion USB key, boot from it, run the Disk Utility from within the installer, delete all partitions and format the resulting space as one OSX partition, proceed to install Mountain Lion.
 

eravulgaris

macrumors newbie
Original poster
Jun 13, 2013
6
0
Since you want to format the entire drive simply make a bootable Mountain Lion USB key, boot from it, run the Disk Utility from within the installer, delete all partitions and format the resulting space as one OSX partition, proceed to install Mountain Lion.
Will this make a difference? Because I did run the Disk Utility from within the installer (CMD + R brings it to the screen with Disk Utility and options to reinstall your OSX)
 

Yahooligan

macrumors 6502a
Aug 7, 2011
965
113
Illinois
Will this make a difference? Because I did run the Disk Utility from within the installer (CMD + R brings it to the screen with Disk Utility and options to reinstall your OSX)
It will make a difference because cmd-R boots off of the internal drive, which you're attempting to reformat/repartition. You can't do that when you're actively using it, so you need to boot off of a device that you're not wanting to wipe and start fresh.