BenWillis0

Q: Changed Macintosh HD permissions. Can't boot into Mac OS X.

Hey.

 

I changed the permissions of the Macintosh HD disk for everyone from Read Only to None to prevent other users on the network from reading the entire disk. Since then, applications wouldn't launch, and now after rebooting, the progress bar stops at just under half way. I'm running the latest version of OS X Yosemite.

 

I've spent some time trying to fix this issue using different methods online.

 

I have attempted:

  • Booting into Disk Utility, repairing the permissions and the disk.
  • Resetting Home Directory Permissions and ACLs using Terminal and the resetpassword command as explained in this article.
  • Restarting with the Command and S keys held down, and entering the following commands from this discussions post:

          mount -uw /

          chown root /

          chmod 1775 /

          exit

 

 

Currently, the progress bar is stuck, however this time, a cursor is displayed, and I'm able to access the Mac remotely using TeamViewer. I guess this shows that something is running in the background.

 

My latest Time Machine backup isn't so recent and may not be complete due to lack of space on the backup drive, therefore I'd hate to have to restore the system using Time Machine.

 

I'm looking for a fix to revert my idiotic mistake. Does anybody have a solution?

Mac mini, OS X Yosemite (10.10.4), mid 2011

Posted on Jul 24, 2015 1:48 PM

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Q: Changed Macintosh HD permissions. Can't boot into Mac OS X.

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  • Helpful answers

  • by Kappy,

    Kappy Kappy Jul 24, 2015 1:48 PM in response to BenWillis0
    Level 10 (270,906 points)
    Desktops
    Jul 24, 2015 1:48 PM in response to BenWillis0

    Boy, you have really screwed the pooch! If you can backup your data, then do this:

     

    Install or Reinstall OS X from Scratch

     

    Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

     

    Boot to the Recovery HD:

     

    Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears.

     

    Erase the hard drive:

     

      1. Select Disk Utility from the main menu and click on the Continue button.

     

      2. After DU loads select your startup volume (usually Macintosh HD) from the

          left side list. Click on the Erase tab in the DU main window.

     

      3. Set the format type to Mac OS Extended (Journaled.) Optionally, click on

          the Security button and set the Zero Data option to one-pass. Click on

          the Erase button and wait until the process has completed.

     

      4. Quit DU and return to the main menu.

     

    Reinstall OS X: Select Reinstall OS X and click on the Install button.

     

    Note: You will need an active Internet connection. I suggest using Ethernet if possible

               because it is three times faster than wireless.

     

    This should install the version of OS X that you had installed.

  • by BenWillis0,

    BenWillis0 BenWillis0 Jul 24, 2015 1:52 PM in response to Kappy
    Level 1 (0 points)
    Jul 24, 2015 1:52 PM in response to Kappy

    I really have! I can still see the data on the drive from Disk Utility. Is it possible to backup my data at this point?

  • by Kappy,

    Kappy Kappy Jul 24, 2015 2:17 PM in response to BenWillis0
    Level 10 (270,906 points)
    Desktops
    Jul 24, 2015 2:17 PM in response to BenWillis0

    I take it that you can at least boot from the Recovery HD. If you have an erased external drive you can connect, then try this:

     

    Clone using Restore Option of Disk Utility

     

      1. Open Disk Utility in the in the Utilities menu.

      2. Select the destination volume from the left side list.

      3. Click on the Restore tab in the DU main window.

      4. Select the destination volume from the left side list and drag

           it to the Destination entry field.

      5. Select the source volume from the left side list and drag it to

          the Source entry field.

      6. Double-check you got it right, then click on the Restore button.

     

    Destination means the external backup drive. Source means the internal startup drive.

     

    This will clone the entire drive to the external drive. Once you get a new copy of OS X onto the internal drive you can restore your data from the backup drive using Drag and Drop. You will have to restore only the contents of the data folders in your old user account, not the folders themselves. Ignore the Library folder if it's visible.

     

    You probably will need to fix the permissions within your Home folder, but check them out before you do. There is a specific method for repairing the permissions in a Home folder, so don't start making your own changes, OK? Follow instructions in Step 1 of Reset a Mac OS X 10.7 Lion Password to get this window:

     

    Screen Shot 2015-07-24 at 2.10.05 PM.png

     

    At the bottom you see Reset Home Folder Permissions and ACLs. Select your volume at the top, then select your user account from the dropdown menu. Skip to the bottom and click on the Reset button.