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How to repair boot disk/startup disk with Disk Utility in Mac OS X?

How to repair boot disk/startup disk with Disk Utility in Mac OS X?

In Mac, there is a disk repairing app called Disk Utility that can used to repair disk permissions, delete a corrupted disk, scan connected drives for errors and also check the structure of disk for technical errors.If your Mac is not booting properly, don’t worry, just use OS X’s recovery mode to repair malfunctioning startup disk.

Just go through these steps to know the complete process –

Start Mac in Recovery mode –

While starting your Mac, press CMD + R to start your system in recovery mode. Once Mac’s booting process gets complete, you are redirected to Utilities screen. On the Utilities screen, select Disk Utility.
Go to menu and choose your startup disk that you want to repair. Then tap on First Aid and proceed to next step. Now Disk Utility will run its operations and try to repair your boot disk. Wait for a few moment as the repairing process will take some time.

Run Repair Disk Function –

After booting Mac in recovery mode, run the repair function. Once your Mac booted into Recovery mode you will see some Disk Utility limitations will get erased completely.

  1.  Hold Command + R keys simultaneously to boot your Mac in recovery mode.
  2.  Next, navigate to Boot menu and choose “Recovery HD”.
  3.  Now, you are redirected to Mac OS X Utilities screen where you have to choose “Disk Utilities” option.
  4.  To repair the boot volume, you need to tap on “Repair Disk”.

The repairing process might take a few moments if various errors get detected. On the other hand, if no problems detected then the repairing process will complete in just fraction of seconds.

Perform First Aid repairing process on your startup drive –

  1. Restart your Mac by pressing Command and R keys to boot from Recovery HD volume. Now you will see OS X Utilities screen on Mac’s screen.
  2. Choose Disk Utility and tap on Continue (Recovery HD).
  3.  Now, Disk Utility window will appear on the screen where you have to tap on First Aid to choose that function of Disk Utility.
  4.  Next, tap on the icon of your boot hard drive that is located at left pane of Disk Utility screen.
  5. The tap on Repair Disk button and close Disk Utility by clicking on “Quit Disk Utility”. Now your Mac will reboot.

Additional method to repair Disk errors in recovery mode –

  1.  Navigate to Apple menu and choose Restart option.
  2.  As your Mac restarts, just hold down the Command and R keys until you hear startup sound and Apple logo displays on Mac’s screen.
  3. Now you will see OS X Utilities screen where you have to choose Disk Utility and then tap on Continue button.
  4. Move to the sidebar and choose the volume that you want to repair.
  5. Tap on First Aid button and then click on Repair Disk.

Now you will face two things i.e., either the app will describe that your disk is OK or you need to perform these further steps –

  •  If you face “overlapped extent allocation” errors then you should understand two or more files have occupied the same space on your disk or one of them is corrupted. At this moment, you have to check each listed file and after that recreate that one. Examine the file data, if possible then delete it.
  • If you receive “The underlying task reported failure” error then you should understand the boot disk is not fully repaired. In such situations, again run Disk Utility and repair the corrupted disk.
    If this is not working then back up your Mac data using Time Machine. Then reformat the disk and reinstall your Mac OS X.

Hopefully, you will be able to repair Mac OS X’ s startup disk. If you have any query or even suggestions then please let us know in the comment section.

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