How to fix external drive not mounted in Disk Utility?

Posted by Katrina to Mac Data Recovery on November 29th, 2018

Mounting a disk simply means to make the disk accessible through the computer's file system. Once you mount a disk, you are able to read and write to it. Normally, most disks are automatically mounted by the operating system when they are connected. If everything is fine, the disk should be visible on the left-hand-side menu of Disk Utility.

But there are times when your connected external hard drive, USB flash drive, SD card or memory card is not mounted in Disk Utility. This article covers troubleshooting solutions to external drive not mounted in Disk Utility.

Do some basic checks

1. Check if the external drive is properly plugged in.

2. Check the external drive is powered on if necessary.

3. Check the condition of the cable and try a different one if you have a spare.

4. Try a different port or outlet if there is one nearby.

5. Reboot your Mac computer to see if it was an open program or app stopping the external drive being mounted.

6. Try connecting the external drive to another computer to see if it is mounted in Disk Utility.

Fixes for external drive not mounted in Disk Utility

If these basic checks above fail to fix external drives not mounted in Disk Utility, you can try the following three fixes:

Fix 1: Run First Aid to repair the external drive

Step 1: Launch Disk Utility.

Step 2: Choose the unmountable external drive from the left sidebar.

Step 3: Click the 'First Aid' tab on the top.

Repair unmountable external drives via First Aid

Fix 2: Repair the external drive with Terminal

Step 1: Go to Applications > Utilities > Terminal

Step 2: Enter diskutil list. This will list out the available volumes.

Step 3: Check the volume identifier from the table that appears. (For example disk 2s)

Step 4: Enter diskutil repairVolume/disk 2s. (Replace disk 2s with the volume identifier of your external drive)

Fix 3: Recover data and erase the external drive

If external drive is still not showing up on Mac, the drive might be corrupted. As any further operation will write new data which overwrites the original data, you'd better at first recover data from the unmountable external drive with iBoysoft Mac Data Recovery.

iBoysoft Mac Data Recovery can recover deleted/lost files from emptied Mac Trash, recover data from formatted, inaccessible, corrupted, unmountable, unreadable drives, including hard drives, external hard drives, USB flash drives, memory cards, SD cards, etc. It's fully compatible with macOS Mojave 10.14/High Sierra 10.13/10.12 and OS X 10.11/10.10/10.9/10.8/10.7.

Step 1: Download and install iBoysoft Mac Data Recovery on Mac.

Step 2: Launch iBoysoft Mac Data Recovery.

Recover data from unmountable external drive on Mac

Step 3: Select the unmountable external drive and click "Next" button to scan for all the lost data.

Step 4: Preview the searching results, choose files you need, and click "Recover" to get them back.

Step 5: Launch Disk Utility.

Step 6: Select the external drive from the left sidebar of the window.

Step 7: Click the Erase button on the top of the Disk Utility window.

Step 8: Complete the related information (name, format, scheme), then click Erase.

Still have questions?