How to mount an unmountable drive in macOS Mojave/High Sierra?

Posted by Admin to Mac Data Recovery on April 21th, 2017

I have an 1TB external hard drive that suddenly is unmountable - disk utility cannot repair this external hard drive. There are extremely important data and I really need to copy these files out, how to mount an unmountable drive Mac, please help.

Unmountable hard drive Mac

In this situation, external hard drive has been corrupted, Mac operating system fails to mount it and we cannot access the data stored on it.

There are several common reasons which cause Mac hard drive fails to mount, such as file system corruption, volume header corruption, disk Utility failure, Log file corruption, OS malfunction, sudden system reboot. How to mount an unmountable drive Mac and access the data? There are several ways, but the best way is to recover data from unmountable drive and then reformat it with disk utility, then the unmountable drive will be mountable again after format completes.

Repair unmouuntable drive in Mac

Disk utility has the ability to repair unmountable Mac drive, it has a built-in function which called "First Aid", Fist Aid can check the volume for errors and then repair the volume if necessary. After repairing with disk utility, the unmountable drive will be mountable, but sometimes, disk untility cannot repair unmountable Mac drive. In this situation, the best way is to recover data from unmountable drive and then reformat it.

Recover data from unmountable drive in Mac

M3 Mac Data Recovery is the professional Mac data recovery software which can recover data from unmountable hard drive, external hard drive, USB drive, flash drive, etc. in macOS High Sierra 10.13/10.12 and Mac OSX 10.11/10.10/10.9/10.8/10.7 and supports HFS, HFS+, exFAT and FAT32 file systems.

Free Mac data recovery software

M3 Data Recovery can also recover deleted or lost files, recover data from formatted, inaccessible, corrupted hard drive, external hard drive, USB flash drive, memory card, SD card, etc.

Detailed steps: Tutorial to recover data from unmounted drive with M3 Mac Data Recovery

Format unmountable external hard drive

After data recovery is successfully done from unmountable external hard drive, please reformat the unmountable Mac hard drive, then it will be working again.

Step 1: Launch Disk Utility from Utilities.

Step 2: Click the icon for your hard drive in the sidebar on the left.

Step 3: Click the Erase tab along the top of the window and enter the related information.

Step 4: Click the Erase button to start format operation.

After that, the unmountable external hard drive will be mountable after format completes.