How can I partition my Macbook Pro's hard disk? I'm about to install Linux on my new Macbook Pro. In order to do this, I need to resize my Mac OSX partition to allow some free space for Linux. I've booted into the Recovery HD and started "Disk Utility." I then repartitioned my hard drive, resizing the Mac partition to 100GB and leaving the rest as free space for Linux to fill. 

The problem I'm having is that whenever I go to apply the changes, I see an error that says:


  Partition Failed
  Partition failed with the error:    
  
  Couldn't modify partition map because the filesystem verification failed. 


I then verified the disk, it found errors:

Invalid volume file count.
Invalid volume directory count.
Invalid volume free block count.
Volume header needs minor repair.
The volume Macintosh HD was found corrupt and needs to be repaired.


So I repaired it, then verified it, and everything looked fine.

Then I tried the partition again and it failed with:


  Partition Failed
  Partition failed with the error:
  
  Couldn't unmount disk.


Then, I try to boot into the regular OS and try resizing the partition there.

I'm met with the errors mentioned above. Rinse, repeat, get nowhere, repeat.

What's going on here? This seems crazy.
Lion has a hidden partition which contains recovery information. Shrinking the partition, according to an Apple employee, is not supported. He hooked up my MBP to an external hard drive and wiped and reinstalled Lion in order to fix things.

In more detail, what happens is this: When you try and resize the main partition, it doesn't include the recovery partition. When you hit "Apply Changes," it does a checksum to make sure that nothing's accessing the drive. It then gets started, doing another checksum, and discovers that something's changed, breaking the previous checksum.