How to fix Macintosh HD not mounted and recover data?

Updated by Tim to Mac Data Recovery on March 11th, 2020

When your Macintosh HD is not mounted in Disk Utility, your Mac computer won't turn on. How to fix it and rescue the data?

This post has 5 methods to fix Macintosh HD not mounted issue.

Method 1: Repair disk with Disk Utility

After your Mac computer won't boot, you can boot your Mac into macOS Recovery mode and then repair unmounted Macintosh HD.

Steps to repair unmounted Macintosh with Disk Utility:

1. Turn on your Mac by pressing Power button.

2. Press and hold down Command+R keys immediately upon hearing the startup chime. Hold down the keys until you see the Apple logo, a spinning globe or other startup screen. Startup is complete when you see the macOS Utilities window as below:

Mac recovery mode

3. Select Disk Utility and click Continue.

4. Select the unmounted Macintosh HD from the left sidebar of Disk Utility window.

5. Click "First Aid" in the toolbar of Disk Utility window.

6. Click Run to check and repair file system errors.

First Aid

Wait until the procedure is complete. If you get returned a message saying success, restart your Mac and see if your Mac can be booted.

If another message says that disk utility cannot repair the disk, go to next solution.

Method 2: Repair Macintosh HD with Terminal

If Disk Utility failed to repair the problematic Macintosh HD, you can try to fix it with Terminal.

1. Boot your Mac into macOS Recovery mode.

2. Click Utilities from the menu bar and select Terminal from the drop-down list.

3. Enter diskutil list command to list available volumes.

4. Enter diskutil repairVolume/disk 1s.

Replace disk 1s with the volume identifier of your Macintosh HD.

Method 3: Recover data from unmounted Macintosh HD

To rescue data from unmounted Macintosh HD, you need a professional data recovery software.

As a professional Mac data recovery software, M3 Mac Data Recovery can recover data from unmounted, corrupted, unreadable Macintosh HD.

Besides that, M3 Mac Data Recovery recover deleted files even emptied from Trash, recover data from formatted drive, recover data from deleted/lost APFS partition, etc. on macOS.

Steps to recover lost data from unmounted Macintosh HD

1. Run M3 Mac Data Recovery from macOS recovery mode.

2. After M3 Mac Data Recovery is loaded, select Macintosh HD from the storage device list and click Next.

Mac data recovery software - M3 Mac Data Recovery

3. M3 Mac Data Recovery is scanning the lost data from the unmounted Macintosh HD.

Scan lost data from unmounted Macintosh HD

4. Preview documents, photos and play videos, audios, etc. in preview mode.

File preview in M3 Mac Data Recovery

5. Select found files and then click Recover to start data recovery.

Method 4: Restore from Time Machine backup

If you have a Time Machine backup, you can restore the backup and fix unmounted Macintosh HD.

1. Boot your Mac into macOS Recovery mode.

2. Select Disk Utility and click Continue.

3. Select Macintosh HD and click Erase.

Before erasing, make sure you don't lose any data.

4. Return to macOS Utilities window.

5. Select "Restore from Time Machine Backup" and click Continue.

6. Select your Time Machine backup disk as the restore source and then click Continue.

7. Select a backup and then click Continue.

8. Select the hard disk as the restore destination and then click Restore to continue.

9. Restart your Mac computer when the restore is done.

Method 5: Erase the drive and reinstall macOS

If there is no important data or you have recovered lost data successfully, erase the Macintosh HD and reinstall macOS.

1. Boot your Mac into macOS Recovery mode.

2. Select Disk Utility and click Continue.

3. Select Macintosh HD and click Erase.

4. Return to macOS Utilities window.

5. Select "Reinstall macOS" and click Continue.

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