How to Use the Disk Utility Tool on Your Mac
The disk utility tool can help troubleshoot specific disk problems on your Mac. Examples include when multiple apps quit unexpectedly, when your computer crashes, when external devices don’t work as expected, and when the Mac won’t start up. To launch the Disk Utility tool, take the following steps:
- Restart your computer by navigating to Apple Menu > Restart.
- Hold the Command and R keys until you see the Apple logo.
- Click Disk Utility and continue.
- Choose View > Show all Devices.
- Select the disk that you want to troubleshoot.
- Click the First Aid button and click Run.
After the repair process, the Disk Utility tool will issue reports on how the process went. If the reports state “overlapped extent allocation errors,” it means that two or more files occupy the same space on the disk that you have just tested. It may also indicate that one of them or both are corrupted. If this happens, you might have to delete the affected files.
At times, the Disk Utility tool may fail to repair your disks in which case it will report that “the underlying task reported failure.” When this happens, you might need to format your files, replace the disk or reinstall macOS. Whatever you choose to do, make sure that you back up your data first, so that you can reinstall it later.
How to Use the Apple Hardware Test on Your Mac
Unlike the Disk Utility test, the Apple Hardware test is more comprehensive as it tests all the hardware components on your computer for any malfunction. To perform an Apple Hardware test on your Mac, take the following steps:
- Disconnect all external devices from your computer, except the mouse, keyboard, display, Ethernet connection, and the AC power connection.
- Place your Mac on a flat, hard, and well-ventilated surface.
- Shut down your Mac.
- Turn on your Mac and immediately press the D key. Keep holding this key until the Apple Hardware test icon appears.
- Use the up and down keys or the mouse to select your language preference and hit the Return key.
- To begin the test, press T. Alternatively, choose the Perform extended testing option. This will do a more comprehensive test than pressing T, but will also take longer to complete.
- After the tests are done, you can review the test results in the lower-right section of the Window.
- To quit the test, you can choose to restart or to shut down your computer.
The results of the Apple Hardware test will tell you if there is anything wrong with your computer and if there is, you should take appropriate action.