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How to Repair External Hard Drive Greyed out in Disk Utility?

Updated on Thursday, March 9, 2023

iBoysoft author Amanda Wong

Written by

Amanda Wong
Professional tech editor

Approved by

Jessica Shee

How to Repair an External Hard Drive Greyed out in Disk Utility?

  1. Summary: This post explains why an external hard drive greyed out in Disk utility and how to fix it. It also covers the methods to solve the dimmed partition and erase button. You can download iBoysoft Data Recovery for Mac to save your files.


You plug an external hard drive into your Mac as normal, but the external hard drive is not showing up in Mac Finder nor on the desktop this time. So, you launch Disk Utility to check this drive, only to find that the external hard drive is greyed out in Disk Utility. You can calm down first because if you see the external hard drive in Disk Utility with some disk information, your external hard drive at least has no hardware errors. That's to say, you have a great chance to repair it without data loss.

Specifically, you might see one of these in Disk Utility:

  •  Fix greyed out external hard drives in Disk Utility
  •  Fix external drives won't mount in Disk Utility
  •  Fix Partition option greyed out in Disk Utility
  •  Fix Erase option greyed out in Disk Utility

The symptoms of hard drive dimmed out in Disk Utility are different from case to case. Therefore, let's first take a closer look at the reasons for this issue before you set about repairing your external hard drive that is faded in Disk Utility.

Table of Contents:

Why external hard drives greyed out in Disk Utility?

Many users are confronted with this annoying issue and are looking for a feasible solution. However, they have no idea exactly why their external hard drives are greyed out in Disk Utility, just like the user from the forum of MacRumors:

"I've been Googling for solutions for the past seven hours. The thing is, I was about to back up and of course, My External Hard Drive in Disk Utility Is Grayed Out!!! My life lives on this disk. I want to also mention that the computer reads the disk. I know this because it appears in Disk Utility, but it's grayed out. Someone helps me."

Then what could be the cause of this problem?

Some common reasons, including sudden power failure, unsafe ejection, virus attacks could make the disk unrecognizable. What's worse, they may damage the file system or partition table of this drive, resulting in disk corruption. If the file system is corrupted too seriously to be read by the operating system, your external hard drive, for example, WD My Passport will be greyed out in Disk Utility.

After knowing what may make your disk greyed out in Disk Utility, now you can suit the remedy to the case by finding the corresponding solutions in the following part.

How to fix when external hard drives greyed out in Disk Utility?

One of the most common appearances you might see is that the external hard drive shows up in Disk Utility but is greyed out in the left sidebar. What you can do in this situation?

Solution 1: : Try to mount the external hard drive manually

Sometimes, your external hard drive is greyed out in Disk Utility just because it was not mounted. Thus, you try to mount this external hard drive in Disk Utility manually. To do this, you can select your external drive and click on the "Mount" button at the upper menu bar. If the hard drive won't mount in Disk Utility still, reboot your Mac and try again.

Solution 2: Update the disk driver and extension

Another practical solution to this issue is to update the necessary drivers and extensions. To update an outdated disk driver, you can simply open your App Store and choose the available one to update.

Or if you receive some errors like "System Extension Blocked", it means a disk driver on your Mac is not working due to the lack of an extension, and you can easily enable this extension to be loaded in "Security and Privacy". After updating the disk driver or extension, you can reboot your Mac, reconnect the external drive to your Mac, and then remount this drive.

How to fix when external drives won't mount on Mac?  

The external hard drive shows up in gray but won't mount in Disk Utility, even you have tried to manually mount it? Don't worry, you can check the following solutions and see if they can solve your problem.

Solution 1: Repair this external hard drive with First Aid

In some cases, a disk is unmountable and greyed out in Disk Utility because some minor disk errors are stopping your Mac from reading this drive. Fortunately, there is a built-in utility on your Mac called First Aid is able to check and repair such minor file system errors.

  1. Go to Utilities, find Disk Utility and run this program.
  2. Click Show All Devices in View option and select this external hard drive in the left sidebar.
  3. Click First Aid in the top menu of Disk Utility.
  4. Click Run to check and repair errors in this drive.

Solution 2: Reformat this external hard drive

Suppose First Aid failed on the external hard drive and you still can't open it, your drive is greyed out in Disk Utility because the file system of the drive could be seriously corrupted. Reformatting can fix the file system corruption, but it also will erase all data on it.

Therefore, if you didn't back up data before or this external hard drive is used as a Time Machine backup drive, the safe choice is to recover lost data firstly with reliable data recovery software, like iBoysoft Mac Data Recovery. If data loss is not a hassle for you, you can just skip to reformatting.

iBoysoft Data Recovery for Mac is professional Mac data recovery software, which can recover lost data from unmountable/formatted/inaccessible external hard drives. It can recover lost data from APFS, HFS+, HFS, FAT32, and exFAT formatted external hard drives, USB drives, flash drives, sd cards, CF cards, memory cards, etc. This software also can undelete documents, pictures, emails, music, etc. from Trash.

It supports macOS 12 Monterey, macOS Big Sur 11, macOS 10.15 (Catalina), macOS 10.14 (Mojave), macOS 10.13 (High Sierra), macOS 10.12 (Sierra) and Mac OS X 10.11 (El Capitan), 10.10 (Yosemite), 10.9 (Mavericks), 10.8 (Mountain Lion), 10.7 (Lion) and works fine on M1, M1 Pro, and M1 Max Mac.

Step 1: Recover lost data with iBoysoft Data Recovery for Mac

1. Download, install and launch iBoysoft Data Recovery for Mac on your Mac.

2. Select the external hard drive that is greyed out in Disk Utility and click Search for Lost Data to scan for data stored on this drive. 
Scan the grayed out external disk for lost data

3. Once the scanning is done, you can open the Complete result on [file system] folder to check the recoverable files. 
The complete scanned results of the grayed out external har drive

4. Select a file and tap Preview to view the contents. 
Preview files

5. Check the box next to the wanted file and click Recover to save the file to another healthy storage device. 
Recover files from the grayed out external hard drive

Step 2: Reformat this external hard drive with Disk Utility

• How to format external hard drives on Mac?

How to fix when Partition external drive greyed out in Disk Utility?

It is possible that an external hard drive is greyed out in Disk Utility, so you try to reformat it by re-partitioning it. However, the Partition feature is greyed out as well. How to fix this problem? Well, you have two options to try.

Solution 1: Check if the external hard drive is NTFS formatted

As you probably know, most external drives would be formatted with the Windows NTFS file system by the manufacturer, while the NTFS file system is read-only on Mac computers. That's to say, you can't perform any input operation to this disk, including re-partition.

So have a check if this external disk is a Windows NTFS file system by viewing the disk information directly. If so, you may need an NTFS for Mac driver so that you can rearrange the space of this disk by partitioning it in Disk Utility.

Solution 2: Enable Show All Devices in Disk Utility

What if your external disk is not formatted with NTFS but some other file systems like Mac OS Extend and FAT, how to fix this issue then? Well, it's likely that the Partition option is greyed out in Disk Utility because you select the wrong item.

You can't partition a volume (Even though the Partition option is highlighted for APFS volumes). Instead, you should select the disk drive when you want to partition a disk, and the following steps would be helpful.

1. Open Disk Utility like you usually do.

2. Click the View icon at the upper left, and then choose Show All Devices in the context menu.                

show all devices in Finder

3. In the left sidebar, you should select the name of the external drive instead of the single volume.

4. Then the Partition feature will not be greyed out and you can click it to partition your disk now.

How to fix when Erase hard drive greyed out in Disk Utility?

Another problem you might meet in Disk Utility is that you can erase a disk because the Erase option is greyed out. Usually, it happens when you try to erase an internal drive, which is reasonable because you can't erase the startup disk that you are currently running.

Then if you want to install a new OS, or if you need to erase personal data before you donate your Mac, how can you erase a system volume?

Solution: Erase the disk in macOS Recovery mode

1. Reboot your Mac and immediately press and hold Command + R to boot your Mac in macOS Recovery mode.

2. Then choose Disk Utility in macOS Utilities.

disk utility in recovery mode

3. Select the volume you want to erase and click on Erase as usual.

• What to do when Mac Recovery mode not working

 Note: Be sure you have an up-to-date backup of your important files and data. But if you lost some important data in this process, you can try iBoysoft Mac Data Recovery to recover your data.


However, if your external hard drive is greyed out in Disk Utility, and the disk information and the storage capacity is not even showing up correctly, the disk may die from physical damage. If this is the case, you can try your luck by sending it to a disk repair service.

It will be great if this article has helped you repair the external hard drive that is greyed out in Disk Utility.