Wait until the operation completes, then quit DU and return to the main menu. If no errors are reported click on the Repair Permissions button.

If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. (SMART status is not reported on external Firewire or USB drives.) If the drive is 'Verified' then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If it does not say 'Verified' then the hard drive is failing or failed. In the DU status area you will see an entry for the S.M.A.R.T. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. When the recovery menu appears select Disk Utility. Repair the Hard Drive and Permissions as follows. Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu.

Select the Recovery HD and click on the downward pointing arrow button. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Reinstalling Lion/Mountain Lion Without Erasing the Driveīoot 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. If the hard drive has not failed, then try this: