7 Replies Latest reply: Jul 30, 2012 12:45 PM by living420
living420 Level 1 (0 points)

Whenever I try to install the latest preview of Mountain Lion, it says"Some features of OS X Mountain Lion are not supported for the disk "R2iMac". The warning directs me here: http://support.apple.com/kb/HT4649


It seems like it'll let me continue, but once it restarted it eventually said the installation failed.


The point is I do have a Recovery HD and I don't know what to do about this. Check out my partitions:

Screen Shot 2012-06-12 at 11.07.04 PM.png

And here's the error dialouge:

Screen Shot 2012-06-12 at 11.08.44 PM.png


Please advise. Thanks.



iMac 2.4 Ghz Intel Core 2 Duo 24", Mac OS X (10.6.4), 4GB RAM
  • Wayne of America Level 2 (220 points)

    You should be asking questions regarding Mountain Lion (10.8) in the Developer Forums where you signed up.

  • JGRF123 Level 1 (0 points)

    I am getting this exact problem while trying to upgrade to mountain lion from the app store. My partitions are exactly the same as yours. Did you solve your problem?



  • living420 Level 1 (0 points)

    Yeah. Unfortunatley, I ended up making a Time Machie backup of my iMac's internal drive and totally reformatting the thing. It did the trick, no problem. Mountain Lion did a perfect job of putting everything back from the time machine. It's not a bad option if you've got some external space to spare.


    Although I understand if you don't have enough space (I didn't either at first). There are supposed to be other ways olf fixing this problem. Now that Mountian Lion has been released, I imagaine people around here will actually help you. So, you should start a new thread about this. Feel free to copy or reference my post, or whatever.


    Good luck.

  • Shootist007 Level 6 (16,660 points)

    Both Lion and now MT Lion have a problem installing on some Mac. It is linked to partition size, somehow.


    The fix is to shrink the main Macintosh HD partition slightly ( in your case whatever the main partitionis called), 100MB to a few GBs. And then the install will go through.


    There is an Apple KB article about it with instructions. Search for "The OS can't be installed on this partition" (or something like that).

  • Culff Level 1 (0 points)

    Living420, I am trying to resolve the same issue you have had when installing MT Lion. I've just got a External drive and done a Time Machine backup of my internal drive. How did you then reformat the internal drive?


    Could you describe what you did next in a bit more detail and as simply as possible for those of us that get lost easily. This would be incredably helpful, Thankyou.

  • living420 Level 1 (0 points)

    You also need to have the Mountain Lion installer ready to go. Either on a thumb drive or some other partition.


    I believe I booted into the recovery drive, opened Disk Utility, and formatted it to Mac OS Extended (Journaled). Then I booted into the installer and it ran fine. And then after it installs it will ask you if you want to restore from a Time Machine backup.