If you have problems with your disk, use Disk Utility on your Mac to test and repair If Disk Utility reports “overlapped extent allocation” errors, two or more files.
If running First Aid doesn't fix the error, then you may need to reformat the hard drive with Mac OS X Extended Journaled file system using.
If you are able to fix the hard drive or SSD in your Mac (or a external drive) as long as the drive failure isn't too terminal, a restart in Recovery.
DiskWarrior: This is a useful disk repair utility for Mac with quite a different repairing functionality, unlike other disk repair tool. The software.
If you have an extra hard drive we will walk you through the process of testing, repairing and stressing the drive to ensure it's in good shape.
If you experience these issues on Mac, your disk may need recovery: multiple apps quitting unexpectedly; corrupted files and access errors.
The Disk Utility identifies and repairs S.M.A.R.T. errors on the hard drive. 5. Reboot the computer Apple Software Restore Disk (for disk checking on a Mac) .