I currently have my MacBook Pro set up to dual boot OS X Lion and Windows 7. I am in the middle of a development project where I need to write some custom software that depends on proprietary drivers that only work in Linux. I have been using a vm but it's getting tedious. It would be nice to be able to boot up into Ubuntu natively.

Currently I have one 500 GB drive that has a 130 GB Windows 7 partition (bootcamp), Lion recovery partition, and my OS X Lion partition with the remaining space. When I try to partition the space i get "Partition failed, couldn't modify partition map because file system verification failed".

I am doing this through Disk Utility running from a Lion recovery flash drive. First aid shows no errors on the drive, but I repaired it anyway and still I get the same error when I try to repartition.

As a last effort I thought it might have to do with fragmentation of the free space so I defragged the drive (against my better judgment) using iDefrag, repeated the above process from USB recovery disk and still I get the same error.

What is the most efficient way to get 4 partitions: OS X, Lion recovery, Windows 7, Ubuntu Linux (booting using refit) without having to wipe everything and reload (reloading OS X and Windows 7 would be unpleasant)?

3 Answers 3


You should be able to use iPartition to solve this problem. I've had a lot of success with re-partitioning drives that failed when trying to use Disk Utility. It also depends on the partition scheme on the drive. If the scheme doesn't support repartitioning you will have to wipe the drive and start fresh.

I would suggest a GUID partition scheme.


I can't speak directly to how this works in Lion, but on 10.6.8, you cannot repartition your startup disk on the fly. You have to erase and reinstall first. On the initial installation procedures, you then use Disk Utility to partition and format the disk as you'd like it. You can use Boot Camp to set up partitions ex post facto, but that is restricted to Boot Camp only (again, this is in relation to Snow Leopard, but I imagine the process is the same for Lion).
I hope I am wrong about this so that you don't have to spend hours reinstalling your stuff. Good luck!


Partition the disk while you're booted on it not from the recovery disk.

  • I have not tried this, but it may be a very bad idea. Dec 21, 2012 at 11:01
  • If you don't do it this way you get "can't unmount disk" errors. Dec 21, 2012 at 14:41
  • you want to repartition the boot disk? tried? Dec 21, 2012 at 14:46
  • Yes, I repartition my boot drive whenever a new osx comes out so I test it a bit before moving everything Dec 21, 2012 at 20:55

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