How to Fix Corrupted Hard Drive on a Mac: Best 4 Methods

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repair corrupted hard drive

A corrupted hard drive is an inevitable part of owning a computer, whether it’s a MacBook or a Windows machine. Aside from having to spend for a new drive, the worst part of a corrupted hard drive is data loss – users commonly lose access to the data on those drives once it gets corrupted.

In this article, we tell you the early warning signs of a failing or corrupt hard drive, a way to recover data from that drive, and finally how to fix the drive by yourself.

Common Signs of Hard Drive Corruption

In most cases, you’ll get a few warning signs before your corrupted drive fails. And while both Windows and Mac operating systems have features in place to warn you, they don’t always show up in time. Watch out for these signals:

Symptoms Description
🐌 Performance Issues Slowdowns, freezing, unusually slow copy-pasting
👂 Weird Noises Beeping, loud humming, clicking noises coming from your drive
💻 Bad Sectors When part of drive becomes damaged and unusable (and is marked by your operating system as such)
🤖 S.M.A.R.T. Errors S.M.A.R.T. stands for “Self-Monitoring Analysis Reporting Technology” – it’s a tool built into most modern hard drives that is meant to log any potential failures. It doesn’t give warnings by itself, but you can use certain tools to check the reports. We’ll talk about this is in the How to Recover Data From a Corrupted Hard Drive section below

How to Recover Data From a Corrupted Hard Drive

Before attempting hard drive repair, you should always make sure that you recover and back up your data first. Fortunately, modern data recovery tools make it pretty straightforward to recover deleted or lost files from your drive without professional help. For this article, we’ll be using Disk Drill.

Step 1 If it’s your internal drive that got corrupted, plug in an external storage device where you can later save the recovered data.

Step 2 Download and install Disk Drill.

Step 3 Open Finder by clicking its icon on your dock.
Finder icon

Step 4 Navigate to the Applications folder and look for the Disk Drill app. Double-click it.
Applications window showing a pointer towards the Disk Drill application icon

Step 5 Select the corrupt drive from the list. If you want to check your S.M.A.R.T. status, you can click S.M.A.R.T. monitoring on the left sidebar and click the “Turn on” button. To proceed with recovery, leave scan settings to “All recovery methods” and click “Search for lost data” at the bottom-right corner of the window.
Storage devices window showing a pointer towards a selected drive and another towards the search for lost data button

Step 6 Wait for Disk Drill to complete its scan. At this point, you can browse through file type by clicking any of the category boxes, or review the full list by clicking “Review found items.”
Disk Drill window showing the types of recovered files and a pointer towards the Review Found Items button

Step 7 You can use the sidebar on the left to filter through file types or use the search bar on the top-left corner of the window for a more precise search.
Disk Drill File Type window with an outline highlighting the file types and a pointer towards the search bar

Step 8 Unlike some other freemium apps, Disk Drill offers unlimited file previews. You can do this by hovering your mouse pointer beside the filenames, and clicking the “eye” button that appears.
a specific file with a pointer towards the eye button positioned beside it

Step 9 Tick the checkboxes beside the files you want to recover or leave all the checkboxes blank if you want to recover all the data Disk Drill found. Once you’re satisfied with your selection, click the “Recover” button at the bottom-right corner of the Disk Drill window.
Disk Drill All Files window showing a pointer towards a ticked box and another towards the Recover button

Step 10 Use the dropdown menu to select the destination folder for your recovered files (in other words, where you want to save them). Make sure to choose a location other than the corrupt drive.

Disk Drill free for Mac does not offer free data recovery, but it does offer free unlimited file previews – this is important for keeping your drive safe. If you cannot preview your files, DIY software will most likely not work and your drive might have suffered physical damage. In this case, send your drive to a professional data recovery center.

How to Fix Corrupted Hard Drive on a Mac

Once you’ve completed data recovery or backed up your data (to a storage device other than the corrupt drive), you can safely continue to repair your hard drive on your Mac. We’ve listed 4 different methods – from the easiest to the most complex – along with easy-to-follow, step-by-step guides for each one. Here’s how to fix a corrupted hard drive on your Mac:

Method 1 Try Another Cable or Port (If It’s an External Hard Drive)

In some cases, your actual drive might not be the problem – it could be the peripherals used to connect it to the computer. If you’re using an external hard drive, you can try using another cable or plugging in your drive to another port on your Mac before proceeding with the other methods.

Method 2 First Aid in Disk Utility

First Aid is a native Apple tool that comes with Disk Utility

Step 1 Launch Disk Utility by opening Finder > Applications > Utilities > Disk Utility.
Applications window showing a pointer towards Disk Utility application icon

Step 2 On the left sidebar, select the corrupt disk. Then, click the “First Aid” button at the top of the window between “Volume” and “Partition.”
Disk Utility window showing a pointer towards the First Aid option

Step 3 On the popup that appears, click “Run.”
Disk Utility popup window with a pointer towards the Run button

Method 3 FSCK Command

FSCK (File System Consistency Check) is a Terminal command that checks the consistency of a file system. Once you run it, it scans and automatically repairs any errors it encounters on your disks. You’ll need to access the Terminal via Single User Mode to use it – and while that can sound a bit intimidating to the uninitiated, we’ve prepared the exact steps so you don’t get lost along the way:

Step 1 Launch the Terminal by opening Finder > Applications > Utilities >Terminal.
Applications window showing a pointer towards the Terminal application icon

Step 2 Type in the following command, then hit enter:

diskutil list

Step 3 Identify the corrupt disk on the list under the “NAME” column, then take note of its corresponding identifier path at the left-most side of the Terminal window. It typically looks like this:

/dev/disk0

Terminal window with a pointer towards the identifier path

Step 4 At this point, you’ll need to enter “Single User Mode.” To do this, restart your Mac, then hold down CMD + S as it reboots.

Step 5 Let go when you see white text on-screen, and wait until it stops scrolling. You should see the following text at the very bottom:

root#

Step 6 Next, type the following command and press enter:

/sbin/fsck -fy “identifier path”

Replace “identifier path” with the path we noted down earlier. For example:

/sbin/fsck -fy /dev/disk0

Step 7 Once the fsck process is complete, type the following command and press enter:

reboot

Method 4 Format the Disk

If all else fails, you can try formatting the disk. The Disk Utility app makes it very easy to do this, but it can again be a bit intimidating for new users. There is also a slight difference in the process depending if you want to fix a corrupted external drive on your Mac or if you’re formatting an internal drive that contains your operating system.

If you’re formatting an external drive:

Step 1 Launch Disk Utility by opening Finder > Applications > Utilities > Disk Utility.

Step 2 At the top of the window, click the “Erase” button to the right of the “Partition” button.
Disk Utility window showing a pointer towards the Erase button

Step 3 On the popup that appears, type in what you want to name your disk, choose the format and partition scheme you want to apply. Once you’re satisfied with the settings, click “Erase.”
Disk Utility popup window showing option to Name, Format, and Scheme and a pointer towards the Erase button

If you’re formatting the drive you’re currently using for your operating system:

Step 1 If you’re using a MacBook with an Intel chip, restart your Mac while holding CMD + R. If you’re using a MacBook with an Apple Silicon chip, shut down your Mac and hold the power button until “Loading startup options” appear on-screen.

Step 2 From the list, select Disk Utility then click “Continue.”

Step 3 Click View > See All Devices and click the dropdown arrow beside your startup disk in the left sidebar. The default name for that disk is usually something like “Macintosh HD.”

Step 4 Select the “Data” volume and click the minus button (-) above “Volume” at the top of the  Disk Utility window.

Step 5 Select the “Data” volume and click the minus button (-) above “Volume” at the top of the  Disk Utility window.

Step 6 Click “Erase Volume Group” on the popup that appears.

Step 7 On the next popup, name your newly erased disk and choose its format (APFS is usually the best choice), and click “Erase.” Enter your Apple ID if prompted.

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