Disk utility major problem

Discussion in 'Mac Basics and Help' started by Talkingtoaster, Apr 18, 2016.

  1. Talkingtoaster macrumors regular


    Aug 19, 2014
    image.jpeg Please help with this, I don't know how I managed to mess this up. What can I do to fix? Was doing a clean install wand wanted to erase the disc.
    --- Post Merged, Apr 18, 2016 ---
    In meantime I have plugged in a blank external drive and installed OSX on that. Do you think after that if I do a clean install a master boot record will show up?

    Have I 'bricked' my MacBook?
  2. Fishrrman macrumors G5


    Feb 20, 2009
    If you placed your computer into my hands right now, I'd do this:

    First, you have installed OS X onto an external drive, this is what you said?
    I'd connect the external drive and boot up from it.

    You may need to set up a basic administrative account before going further. (you may have already done this)
    I would PASS on setting up any account info with Apple for now.

    Can you get to the finder?
    If so, are you able to mount the INTERNAL drive on the desktop?
    Does it mount? If so...

    ...Is there anything on it you want to save?
    If so, copy that immediately to another drive (could be the external from which you're booted)

    Next, open Disk Utility again.
    "Aim it" at the internal drive. (Click on the "disk1" line)
    Can you erase it?

    If so, give it a name that's meaningful to you.
    I would also run Disk Utility's "repair disk" on it once or twice, making sure you get "a good report" each time.

    Next, download CarbonCopyCloner from here:
    CCC is FREE to download, and it's FREE to use for the first 30 days.

    Now, open CCC.
    On the left (the "source") you want your external, bootable drive.
    On the right (the "target") you want your internal drive.

    CCC also has a preference to clone over the recovery partition as well.
    Make sure this option is selected.
    You also want to be sure that your clone is a full replacement - CCC should be set to "delete anything that doesn't exist on the source".

    Now let CCC do its thing.

    When done, quit CCC and open the Startup Disk pane in System Preferences and set the internal drive to be your boot drive.

    Now I suggest you power down the Mac -- ALL THE WAY OFF.

    Disconnect the external drive and reboot.

    What happens?
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Boot back to recovery like you did before then in the Utilities menu open Terminal. Then run the command below. That should remove the core storage volume I believe we are seeing at the top there in Disk Utility.

    diskutil cs delete "MAC OSX"
    Then quit Terminal and go back to Disk Utility. Go to the erase tab and select the internal drive then format it to Mac OS Extended (Journaled). Then quit Disk Util and you can reinstall the OS.
  4. Talkingtoaster thread starter macrumors regular


    Aug 19, 2014
    Your are both TOTAL LEGENDS! Thank you so much guys, genuinly thanks so much! All sorted now, and on the plus side my mum thinks I'm a Mac genius....but in the end I said i found help on this forum!!

    Thanks again to both your of you :)
  5. Ebenezum macrumors 6502a

    Mar 31, 2015
    I'm glad that you managed to get the Mac working again.

    However next time you are thinking about clean install make sure to:

    1. Backup your Mac (use software such as SuperDuper! or Carbon Copy Cloner) and disconnect backup drive before opening Disk Utility!

    2. When using Disk Utility be careful and make sure your selections are correct before confirming choices. You don't want to be in a same situation again...
  6. Talkingtoaster thread starter macrumors regular


    Aug 19, 2014
    Noted, thank you for the advice :)

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