I have an MBA 2009, model A1304. The Hard drive system information says its an "Apple SSD SM128". But when I look at the available and total space, I have one partition 28.8GB (bootcamp) and one 38.8GB (Main MacOS). Those are the total sizes. They come to 67.6GB. Now I read many forum posts complaining on 5GB lost here, 10 there. But this is like half the SSD drive. Could it be that its going bad and half of it was marked off limits or something.

When I boot the machine to MacOS, it shows a similar state.

When I look at the Admin tools > System management > Storage > Disk Management screen in Windows, it shows a 45GB "Unallocated space" partition, which is invisible under MacOS. I guess this is the missing space. Can I format it and use it under Windows? can MacOS or BootCamp be using half the SSD drive for its housekeeping usage?

Bootcamp 3.2, OSX 10.6.7

Interestingly, the Mac OS partition utility also shows a 45GB area unused between the partition, which it lets me use to expand the Mac HD partition. (I didn't do it yet, only on the interface then cancelled). But its very strange - this Mac Air started as an MacOS only device; presumably (I don't remember ever checking it then) the Mac HD partition originally used all of the SSD space, as factory configured by Apple. I then installed Bootcamp. Could Bootcamp have thrown away half the hard drive space in to an unused partition, and for what purpose would it have done that?

I would like now to format this partition to be used by Bootcamp (i.e. Windows) not the Mac OS. So there should be no harm to the MacOS if I go to windows and format it?

I would appreciate any help in tackling this.

Screenshot of MacOS Partition info:

  • General SSD info: enter image description here

  • Partitions with unused area in gray: enter image description here

  • Mac OS X allows expanding OS HD with usused area:

    enter image description here

  • I have a similar problem with Macbook Mid 2007, a bug in Bootcamp: I am unable to install any other OS side-by-side to Apple OS X and now unable to restore the storage space. My Apple guru friend said that this may be a hardware bug, software bug or intentional "upgrade" by Apple to make people move to newer models.
    – hhh
    Mar 4, 2013 at 0:37
  • 2
    Unfortunately, Bootcamp does not take kindly to simple methods of resizing its partitions. See this question for info. apple.stackexchange.com/questions/388/…
    – Chris A
    Mar 4, 2013 at 4:30
  • I wouldn't even conclude bootcamp is the problem, but it does seem to introduce partitions that OS X and Disk Utility are less than eager to modify or do things like a live resize once you delete or change partitions after it's been partitioned.
    – bmike
    Apr 30, 2013 at 17:35

1 Answer 1


I would back that drive up and then erase it entirely.

You should get a clean single partition out of Disk Utility and then be able to tell if the hardware needs to be servicesd or it was just a problem with partitioning or data corruption and fixable by a clean start.

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