How to Recover Data from Unmountable Hard Drive on macOS/Mac OS X

Daisy updated on Feb 21, 2019 to Mac File Recovery | How-to Articles


File system corruption, Disk Utility failure, or OS malfunction are all likely to make your hard drive unmountable. When you encounter such an issue, you are suggested to recover data from the unmountable hard drive on your Mac as soon as possible with a tool like EaseUS Data Recovery Wizard, then repair the unmountable drive.

Recover Data from an Unmountable Drive on Mac
Repair an Unmountable Hard Drive on Mac

Part 1. How to Recover Data from Unmountable Drive on macOS/Mac OS X

"To recover unmountable hard drive under macOS or Mac OS X sounds complex and troublesome to me. Have you ever been troubled by an unmountable hard drive on your Mac? Take myself, for instance, I started my Mac Mini this morning and it suddenly stopped running, telling me an unmountable error happened to my Mac volume. I can't get access to this volume and I got quite a lot of important data and files in there. What should I do?"

Usually, the "unmountable hard drive" issue on Mac happens when you boot up your computer. During the booting process, your Mac operating system will mount the local file system and read data on Mac drives. If your macOS or Mac OS X could not get access to the drive or file system, the "unmountable hard drive" problem will occur. There some basic information about this issue:


  • The hard drive will be greyed out in Disk Utility
  • All data that is stored on the unmountable drive will be inaccessible

Possible Causes

  • Virus/malware infection
  • Files system corruption
  • OS malfunction
  • Disk Utility failure


When you get an unmountable hard drive on your Mac, what flashes into your mind first is likely to be how to rescue the files on it. Fortunately, although you can't access the files on the problematic hard drive directly, you can still recover your files on the unmountable hard drive on your Mac with professional Mac data recovery software - EaseUS Data Recovery Wizard, which enables you to recover over 200+ file types from your Mac hard drive or compatible external storage devices in various tough situations. For example:

With this tool installed on your Mac, you can securely recover the data from the unmounted hard drive on your Mac.

Steps to Recover Data from Unmountable Hard Drive on Mac

Step 1. Select the disk location (it can be an internal HDD/SSD or a removable storage device) where you lost data and files. Click the Scan button.

select the location where data lost and click scan

Step 2. EaseUS Data Recovery Wizard for Mac will immediately scan your selected disk volume and display the scanning results on the left pane.

scan the selected disk to find lost data on your Mac

Step 3. In the scan results, select the file(s) and click Recover Now button to have them back.

click recover now button to recover lost data on your Mac

EaseUS Data Recovery Wizard for Mac allows you to recover unmountable hard drive on your Mac in simple steps. It is also capable to settle troublesome data lost cases like how to recover Mac hard drive. It's 100% clean and secure for helping users to solve all Mac data problems with full solutions for Mac hard drive recovery. Don't hesitate to give it a try.

Part 2. How to Repair Unmountable Hard Drive on Mac

After recovering data from the unmountable hard drive on your Mac, now you can repair it without being worried about data loss. To repair an unmountable Mac hard drive, you can use the First Aid feature in Disk Utility or format the hard drive directly.

Method 1. Repair an Unmountable Hard Drive on Mac with Disk Utility

Disk Utility can fix some disk problems, it's well worth trying when your Mac hard drive gets unmountable.

Step 1. Go to Apple Menu and click "Restart". Then press and hold "Command + R" immediately until the Apple logo appears.

Step 2. Click "Disk Utility" > "Continue".

Step 3. Choose "View" > "Show All Devices" and select the drive you want to repair in the sidebar.

Step 4. Click the "First Aid" button. If Disk Utility tells you that your hard drive is about to fail, back up your data and replace it with a new disk. Otherwise, move on to the next step.

Step 5. Click "Run". If Disk Utility tells you that the disk has been repaired, you can use your hard drive normally again. If not, format your unmountable hard drive to repair it.

Method 2. Repair an Unmountable Hard Drive on Mac by Formatting

Step 1. Go to "Finder" > "Applications" > "Utilities" > "Disk Utility".

Step 2. Select the drive in the left sidebar and click "Erase".

Step 3. Click Erase to confirm the formatting.


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Frequently Asked Questions

1. Why choose EaseUS Data Recovery Wizard?

"EaseUS Data Recovery Wizard is the best we've seen. It's far from perfect, partly because today's advanced disk technology makes data-recovery more difficult than it was with the simpler technology of the past, but it's fast and efficient..."PCMag

"The first thing you'll notice about EaseUS Data Recovery Wizard Pro is that its interface is very clear and uncluttered, with only a small collection of self-explanatory controls. You won't find lots of extra options hidden in a system of hidden menus, either; what you see really is what you get."techradar

"Recover lost files, even after deleting a partition or formatting your drive."Macworld

2. Why cannot I recover 2GB data for free?

It is recommended to check the version installed is Free or Trial because they are different versions.

Trial has data preview function but cannot save any files, while the Free version enables to recover 2 GB files. The default free space is 500 MB and you may share the product on social media to get another 1.5 GB.

3. Why cannot the recovered files be opened?

A file is saved as 2 parts on the storage device: directory info (which is comprised by file name, time stamp and size info, etc.) and data content.

If the files with original file names and folder structures cannot be opened, one possible reason is the corrupted directory info. There is still a chance to recover the data content with the RAW Recovery method in our software.

4. Why isn't it suggested to recover the files back to the original drive?

The storage structure of the lost files would be altered or damaged by any changes on the drive. If you save the recovered files back to the same drive, the original data structures and data content would be corrupted or overwritten, which causes permanent data loss. So you should prepare another disk to save the files.

5. How can I check whether my data is recoverable or not before purchase?

The Free version helps you save 2GB files, so verify the recovery quality of our product before purchase.

6. How long does it take to scan the drive?

It strongly depends on the capacity of your hard drive and the performance of your computer. As reference,most drive recoveries can be completed in around 10 to 12 hours for a 1-TB healthy hard drive in general conditions.

About Data Recovery Wizard

It's super easy to recover 250+ types of files after deletion, disk formatting and virus infection. Click the links and compare the difference of each version.