Home > Questions

How To Fix No HDD Content After The macOS Sonoma Update?

I updated my Mac Studio to Sonoma, and as soon as I did, the two external HDDs, an OWC Mercury Elite Pro, that were connected, stopped displaying their contents. They mount and can be read by Disk Utility; they show some folders, but the 39TB that is being used is not visible or accessible. I tried first aid, but it didn't work, and I also tried plugging them in another computer, and that worked flawlessly, but I can't work on that other computer. That's what happens when you update your Mac Studio in the middle of a job. Any fixes? Thanks.

Best Answered by

iBoysoft author Vain Rowe

Vain Rowe

Answered on Wednesday, November 22, 2023

It's uncommon to see an exFAT external hard drive show a part of files while hide the rest of them since exFAT is supported by macOS. And the reason behind it is an incompatible exFAT allocation unit size. The allocation unit size, also called cluster size, is the smallest amount of disk space that can be used to save a file.

When Windows formats a drive with a large capacity like 4 TB or above in exFAT, it will format it using the 2048 KB or higher allocation unit size by default, which is incompatible with macOS which can only natively mount exFAT drives with cluster size from likely 512 bytes to 1024 KB, based on user's tests.

So the exFAT allocation size should be the final culprit resulting your drive in hiding files. My advice is to format your exFAT drive to an Apple file system for further usage. Do back up your files on the drive before it is formatted to an Apple file system or the data can be erased.


People Also Ask

Read More Questions

Read More Advice From iBoysoft's Computer Experts

Factory reset MacBook

How to Completely Factory Reset a MacBook Pro/Air?

To factory reset your MacBook, you need to start your Mac in macOS Recovery Mode, wipe MacBook Pro/Air and then reinstall macOS.

Mac Data Recovery Tips




how to open files on mac

7 Ways to Open Any Files on Mac [Easy & Quick]

You open files every time you work on a Mac, and there are many ways to do this. I'll show you Simple ways to open any files on a Mac.

How to Tips