Fixed! External Drive Greyed Out on Mac? Can't Mount/Erase/Partition?

You plug an external hard drive into your Mac as normal, but the external hard drive is not showing up in Mac Finder or 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:

Now let's dive into each scenario! 

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How to fix the external hard drive icon 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: Mount the external hard drive manually

Sometimes, your USB drive is greyed out in Disk Utility just because it was not mounted. Thus, you can 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 it doesn't work, reboot your Mac and try again.

Solution 2: Update the disk driver

Another practical solution to this issue is to update the necessary drivers. To update an outdated disk driver, you can simply open the Apple Menu > System Settings >General > Software Updates, it will automatically check for updates, if there are any available macOS updates, follow the onscreen guide to update the Mac.

After updating the disk driver, you can reboot your Mac, reconnect the external drive to your Mac, and check whether the drive is mounted now.

How to fix the external hard drive won't mount on Mac?

The SSD/HDD/USB flash drive/SD card shows up in gray but won't mount in Disk Utility, even if 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 that can check and repair such minor file system errors.

Solution 2: Reformat this external hard drive

Suppose First Aid failed on the external hard drive and you still can't mount the USB drive greyed out in Disk Utility, 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 haven't backed up data before or this external hard drive is used as a Time Machine backup drive, the safe choice is to recover lost data first with reliable data recovery software, like iBoysoft Data Recovery for Mac. If data loss is not a hassle for you, you can just skip to reformatting.

iBoysoft Data Recovery for Mac is a 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 Mac OS X 10.11 and later versions and works fine on M3, M2, M1, and Intel-based Macs.

Step 1: Recover data from the greyed-out external hard drive with iBoysoft Data Recovery for Mac

5. Check the box next to the wanted file and click Recover to save the file to another healthy storage device. 

Step 2: Reformat this external hard drive with Disk Utility

• How to format external hard drives on Mac?

If this method works to fix the greyed-out external hard drive in Disk Utility, share it with more people!

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

An external hard drive may be 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 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. iBoysoft NTFS for Mac is such an NTFS driver, that automatically mounts the drive in read-write mode, and enables you to partition it on Mac.

Solution 2: Select the correct drive instead of volume

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, the Partition option is likely 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.

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

Another problem you might meet in Disk Utility is that you can't 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

In case it fails, further read this post [Complete Guide] Disk Utility Won't Let You Erase Hard Drives to fix the issue.

Why external hard drive 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 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 USB drive greyed out in Disk Utility?

Some common reasons, including sudden power failure, unsafe ejection, and 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.

Whatever the case, you'd better recover data from the greyed-out external hard drive with data recovery software first if there is no backup to avoid data loss caused by further operations.

Also read:

• NTFS External Hard Drives Not Mounting/Working on Mac (Sonoma/Ventura)

However, if your external hard drive is greyed out in Disk Utility, and the disk information and the storage capacity are 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.

Have already fixed the greyed-out external hard drive in Disk Utility? Let others know the solutions!