How to check hard drive health on Mac?

How to check your Mac's hard drive health status?

Internal storage is one of most important component of your computer, it is place where your operating system and all software lives, due to this reason any crashes within your hard disk (HDD) or flash drive (SSD) might result in inactive Mac, or even worse - data loss. Periodically checking the health status of your hard drive will be a perfect precaution against any data loss or unexpected software crashes. It is not a secret, that hard disks and especially flash drives contains limited amount of write cycles, whether it is internal or external storage.

However, usually you should be able to notice strange issues, before you will loose data or Mac's accessibility, your computer will begin to experience random freezes or freeze while attempting to move files, another common issue, the errors stating that permissions denied, while trying to access the files or data, you've entering daily without any problems. There might be a number of other mysterious issues, relating to failing hard drive. Luckily, Apple included the built-in tool, that is able to check and repair minor damage of your storage, additionally, this method works on both, internal and external storage, despite it's kind, whether it is hard disk drive or flash drive. What is more, there is a method to repair your startup disk by using the file system check function. In this article we will describe the methods how to check your drive health status and attempt to repair some bad sectors and other issues.


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Check your hard drive's health via Disk Utility

As it was mentioned above, you should not wait until encounter with mysterious issues, to check the current status of your hard drive, in order to prevent any data loss or performance decreases, it is recommended periodically inspect your drive. Luckily, it is quite simply to proceed by using the built-in tool related to hard drive, called Disk Utility. Use Spotlight by pressing keyboard shortcut of Command and Spacebar and type Disk Utility, alternatively you may go to Utilities folder under Application via Finder. One you've launched the application, select one of connected drives from the list in the left sidebar. Further, click the First Aid button in the top middle of window, you will be prompted to confirm your action, click Run.


If you're trying to check status of startup disk, another warning will pop up, stating that you're trying to verify booted drive, due to this reason in order to perform a complete check you operating system will be frozen, however, if you're not performing any important active actions click Run, all software will regain it's full functionality immediately when the verification process finishes.


When the First Aid function completes it's work, the result message will be displayed stating, your hard drive is OK, otherwise click Repair disk, if suggested, or try repeating the First Aid procedure until you get result, that your hard drive is OK. Sometimes, Disk Utility is unable to repair booted drive, in this case follow the next method.

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Repair startup disk via macOS Recovery mode

In case you encountered the situation, where Disk Utility is unable to repair your hard drive, when it is booted, there is another way how you may access the Disk Utility, without loading your Mac. However, it is recommended to create the backup of your storage first, the easiest would be to use Time Machine. When you've prepared backup, shut down your Mac, then press and hold Option (Alt), Command, and R while starting your computer. Keep holding until Apple logo or spinning Globe appears, from the macOS Utilities window select Disk Utility.


Further, repeat the procedure to check your hard drive, select one of connected drives from the list in the left sidebar. Next, click the First Aid button in the top middle of window, you will be prompted to confirm your action, click Run. Finally, click Repair disk if prompted, to attempt automatically repair your hard drive. As it was mentioned above, checking your hard drive's health status is a good prevention against unexpected issues and data loss, however, you should not skip creating backups, since there might be a number of cases, when hard drive fails without any signs.


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Use Single User Mode to repair hard drive

Last, but probably most efficient method would be to boot your Mac into Single User Mode and use specific command fsck, that is a shortcut to launch the file system check feature. To begin with, if possible create the backup, then shut down your computer. In order to access this mode, press and hold Command and S immediately after hearing the startup chime, if you managed to access the Single User Mode you will notice, when you see a lot of white text within black display appearing on your screen. Be patient, this boot may take some time, however, once booting is finished, each new line will be prepended with "localhost//", type the following command and press Return to execute.

  • fsck -fy


When the checking process is finished within results you should find message, stating that The volume appears to be OK, otherwise repeat the system check until you receive this message. Finally, type reboot and press Return to exit Single User Mode. Once your computer is completely booted, it is recommended to launch disk check via Disk Utility again, to ensure everything is working properly. If none of these steps could solve your issues related to hard drive, it is recommended to contact Apple Store or any licensed technician.


Video Showing how to check Mac's hard drive health status

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