At the moment I have 1 250GB partition on my mac (Macintosh HD).

What I want to do is split my hard drive into 3 partitions. This is because I want to dual boot with Windows 8.1 and make a reserve drive for when El Capitan comes out so I can test it without my computer becoming buggy. The only issue is I can only split my Mac into 2 partitions. How would I do this? I also tried doing this in recovery mode and it did not work. Would I have to use a 3rd party tool like GParted? If so would it be safe and would I loose my recovery partitions if I do?

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    I have done that dozens of times with disk utility and never had problems. But back up your disk before! – idmean Jun 18 '15 at 17:32
  • @idmean Do you mean you used gparted for that? I also backup everything to the cloud. – iProgram Jun 18 '15 at 18:03
  • Is your disk a Core Storage Logical Volume? Look at the screenshot in this question - specifically "Logical Volume Group" under Type in the lower left - versus Disk Utility on your system. If it is, that is why you cannot partition it further. Do you have a Fusion Drive or encrypted File Vault? There is no way around it then. If you're not using Fusion Drive or File Vault, you should be able to revert to a non-Core Storage volume and partition further. – tubedogg Jun 19 '15 at 0:01
  • @tubedogg Thanks for the tip. I followed the steps in the post (revert to non-code storage) you linked and it worked. – iProgram Jun 19 '15 at 12:43

Thanks to @tubedogg for linking me to this post and giving me the tips.

To fix the issue I had to run the commands diskutil cs revert <disk id> and diskutil cs resizeStack (Not sure if that worked since I think it game me an error).

I had to reboot for the effects to change and I partitioned my drive in recovery mode (think you can do it within OS X though).


You will not be able to split your drive into more than two partitions and still be able to boot Windows. There is a hard limit on the number of partitions on the boot drive for Windows (may be for Mac and Linux too, not sure).

You can certainly dual boot Mac and Windows (or Mac/Linux) but not all three on one drive.

If you follow the instructions in creating bootable windows install media from Bootcamp it will boot from the media and present you with a partition map that allows you to re-partition the HD for Windows/Mac O/S dual boot.

I have found that doing it manually, outside of BootCamp is generally not a good idea for whatever reason.

yes you should be able to boot into recovery mode and adjust the partitioning there. but I would only do that with explicit instructions in front of you for installing your favorite Linux distro. So it is done correctly. Otherwise do the repartitioning of your boot drive with the BootCamp installer.

  • So do you mean it's not possible even outside bootcamp? – iProgram Jun 18 '15 at 21:00
  • See this - what hard limit are you referring to? MBR supports 4 partitions, and in the hybrid MBR configuration used by Boot Camp, it can "see" up to 3 of them. – tubedogg Jun 19 '15 at 0:05
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    You are wrong. I have OS X, Windows, Fedora and rEFInd installed on a 2011 iMac. I don't have Fusion Drive and I am not using Core Storage. Also, Boot Camp is not installed into Windows until after you finish installing Windows. There is no difference between installing Windows using the Boot Camp Assistant and installing Window manually. Windows installs the same as if you were installing on a PC. – David Anderson Jun 19 '15 at 4:38
  • I just installed Windows 8.1 without BootCamp and it worked perfectly. What went wrong when you done it? I also had to revert to a non-core storage partition scheme because recovery mode wouldn't have helped. – iProgram Jun 19 '15 at 12:51

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