External Disks getting detected only intermittently on 14" MacBook Pro

I have a bunch of external hard disks ranging from 1TB to 5TB in size. They are all formatted in ExFAT since I need to transfer footage to Windows computers. However, it is always random whether a drive gets detected by my MacBook. Some disks get mount every time, some never even get detected even though they should (especially the 5TB ones). I have a 14" MacBook Pro with M2 Pro, 16GB RAM and the 512GB Storage option. I'm on the latest version of Sonoma (14.7.1). I always connect through the same USB Type C to Type A adapter, and no matter which port I use the results are similar. The disks sometimes don't even show up in Disk Utility. The disks always show up in Windows or Linux without fail. Only MacOS ever has problems connecting to disks that are working fine hardware-wise. How do I fix it if I can't even see these disks in Disk Utility?

MacBook Pro 14″, macOS 14.7

Posted on Jan 29, 2025 12:19 AM

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Question marked as Top-ranking reply

Posted on Jan 29, 2025 2:18 AM

It looks like these disks may be drawing too much power from the USB port than your mac can provide. If they have a separate power supply, do connect them to power. Otherwise, you may want to try connecting them to a powered USB hub.



14 replies

Jan 29, 2025 3:11 AM in response to Owl-53

PRP_53 wrote:

Issues with external drives and macOs Son… - Apple Community

Quote from my Go To contributor @ HWTech on most things Hardware-wise

Disregard aspects that do not apply to your setup

Quote

" You have neglected to include some very important details such as the file system(s) used on the external drives which have this issue. I'm assuming they are using exFAT or FAT32 file systems. If so, continue reading.....

Apple changed the exFAT and FAT (ms-dos) driver from a Kernel driver to a user space driver so it seems it is still a work in progress, or maybe this is the new normal.

See this Apple article, especially section in the following screenshot:
macOS Sonoma 14 Release Notes | Apple Developer Documentation


https://discussions.apple.com/content/attachment/f95e5da1-9e91-4da2-8f3a-c9db1ba65a9a


Also, here is another similar thread about the issue:
Can’t set folder icons for the folders in…exFAT or FAT32 volumes - Apple Community "

End Quote





Thanks for the information, at least it makes sense that this is an actual issue with how Mac OS handles filesystems. I don't see any fixes to the problem though. Is there any actual solution to the weird intermittency or is it just keep restarting the machine until it recognises the disk when plugged in?

Jan 29, 2025 3:19 AM in response to EzioCrenshaw

Long Shot - if the Mac doesn't see a drive when it's plugged in then try quitting the usbmuxd process. Don't do it if you've got any other USB stuff going on. It might not be a permanent fix, but if it works it will be quicker than rebooting. Like I say, a long shot that used to cure similar problems I had but many OS's ago. You might have to disconnect and re-connect the drive.


Use Activity Monitor app to kill it. Search for the app in Activity Monitor's search then kill it with the X in the toolbar.

Jan 29, 2025 6:30 AM in response to Zurarczurx

Thanks for the response, I will try it next time I get the issue. Premiere is accessing footage on one or another disk though so I will have to keep in mind to quit all the creative cloud apps before trying this.

Zurarczurx wrote:

Long Shot - if the Mac doesn't see a drive when it's plugged in then try quitting the usbmuxd process. Don't do it if you've got any other USB stuff going on. It might not be a permanent fix, but if it works it will be quicker than rebooting. Like I say, a long shot that used to cure similar problems I had but many OS's ago. You might have to disconnect and re-connect the drive.

Use Activity Monitor app to kill it. Search for the app in Activity Monitor's search then kill it with the X in the toolbar.


Jan 29, 2025 2:21 AM in response to EzioCrenshaw

Issues with external drives and macOs Son… - Apple Community


Quote from my Go To contributor @ HWTech on most things Hardware-wise


Disregard aspects that do not apply to your setup


Quote


" You have neglected to include some very important details such as the file system(s) used on the external drives which have this issue. I'm assuming they are using exFAT or FAT32 file systems. If so, continue reading.....


Apple changed the exFAT and FAT (ms-dos) driver from a Kernel driver to a user space driver so it seems it is still a work in progress, or maybe this is the new normal.


See this Apple article, especially section in the following screenshot:

macOS Sonoma 14 Release Notes | Apple Developer Documentation




Also, here is another similar thread about the issue:

Can’t set folder icons for the folders in…exFAT or FAT32 volumes - Apple Community "


End Quote






Jan 29, 2025 7:56 AM in response to Zurarczurx

Zurarczurx wrote:


PRP_53 wrote:

You are 100% correct in that exFat is not NTFS

Though, a possible solution was provided

There has been sufficient advice offered for the User ( you ) to make an informed and educated choice what remedial actions maybe required for this computer.

What the user does with this information is really up to the recipient

The suggestions have been put forth on a volunteer basis, in good faith and in the best interests of the computer.
I've been following this and I struggle to discern any possible solutions in your posts and, TBH, they look as they might come from a chatbot. What was your possible solution?

I would be very careful making such an assertion


Adding information after the fact " They were already formatted in ExFAT on a machine running Ventura, "


Am sure one may have noticed this ?


Solution


Reformat the drives on the MS Windows as NTFS and use the needed software on macOS

Jan 29, 2025 3:04 AM in response to Luis Sequeira1

Luis, the disks work normally on some occasions and not on others, in fact using the same Type C to Type A adapter on any number of bog-standard windows machines, they just work. These are 2.5" form factor drives from Seagate and WD, there is no reason why they shouldn't work. There is no rhyme or reason to the intermittent failure of Mac OS to recognise a disk and load the filesystem.

Jan 29, 2025 3:21 AM in response to EzioCrenshaw

" They are all formatted in ExFAT since I need to transfer footage to Windows computers. " ?


Not always a good idea for multi reason .


The Third Party Software required to Read and Write to MS Windows NTFS formatted drives does often get Broken during updates to macOS


I neither endorse nor use such Third Party Software which is available for Purchase

Jan 29, 2025 3:27 AM in response to Owl-53

PRP_53 wrote:

" They are all formatted in ExFAT since I need to transfer footage to Windows computers. " ?

Not always a good idea for multi reason .

The Third Party Software required to Read and Write to MS Windows NTFS formatted drives does often get Broken during updates to macOS

I neither endorse nor use such Third Party Software which is available for Purchase

Okay, but ExFAT is not NTFS, so your point is irrelevant.

Jan 29, 2025 5:07 AM in response to EzioCrenshaw

You are 100% correct in that exFat is not NTFS


Though, a possible solution was provided


There has been sufficient advice offered for the User ( you ) to make an informed and educated choice what remedial actions maybe required for this computer.


What the user does with this information is really up to the recipient


The suggestions have been put forth on a volunteer basis, in good faith and in the best interests of the computer.

Jan 29, 2025 5:23 AM in response to Owl-53

PRP_53 wrote:

You are 100% correct in that exFat is not NTFS

Though, a possible solution was provided

There has been sufficient advice offered for the User ( you ) to make an informed and educated choice what remedial actions maybe required for this computer.

What the user does with this information is really up to the recipient

The suggestions have been put forth on a volunteer basis, in good faith and in the best interests of the computer.

What possible solution did you provide? Reformat disks? I already said that wasn't possible with certain disks not getting detected in the macOS Disk Utility. They were already formatted in ExFAT on a machine running Ventura, so unless you mean to somehow tell me that MacOS cannot reliably read disks partitioned by the previous version of itself, you offered me nothing there.


I am thankful for your pointing out that the ExFAT driver was moved by Apple from Kernel to usermode, but that is not really useful as a solution to me, it's not something I can change. It's not sufficient to affect the problem.


Then you went off on a tangent about third party software, none of which is being used in this case. The problem is entirely within the native MacOS software. If I were having trouble with Paragon or whoever makes NTFS drivers, I would have mentioned it. Your rants are irrelevant and are not good faith advice in the "best interests of the computer".


Jan 29, 2025 5:28 AM in response to Owl-53

PRP_53 wrote:

You are 100% correct in that exFat is not NTFS

Though, a possible solution was provided

There has been sufficient advice offered for the User ( you ) to make an informed and educated choice what remedial actions maybe required for this computer.

What the user does with this information is really up to the recipient

The suggestions have been put forth on a volunteer basis, in good faith and in the best interests of the computer.

I've been following this and I struggle to discern any possible solutions in your posts and, TBH, they look as they might come from a chatbot. What was your possible solution?

Jan 30, 2025 11:16 AM in response to Owl-53

@PRP_53

You must be a chatbot, because your last response contradicts your earlier stance below:

>" They are all formatted in ExFAT since I need to transfer footage to Windows computers. " ?

>Not always a good idea for multi reason .

>The Third Party Software required to Read and Write to MS Windows NTFS formatted drives does often >get Broken during updates to macOS

>I neither endorse nor use such Third Party Software which is available for Purchase


Your later response was:

>I would be very careful making such an assertion

>Adding information after the fact " They were already formatted in ExFAT on a machine running Ventura, "

>Am sure one may have noticed this ?

Unless mentioning Ventura is a crime on these forums, I fail to see how this sentence of yours is relevant. I could have created the ExFAT partition on Windows Vista for all it matters. A properly formatted ExFAT partition should be readable the same to all computers, and indeed this is the case except the one I have running MacOS Sonoma.


>Solution

>Reformat the drives on the MS Windows as NTFS and use the needed software on macOS

Now you say use NTFS from Windows, and install 3rd party NTFS tools? Did you previously not advise against this exact thing? What caused the change of solution?

And further how is this in anyway related to my problems with ExFAT?

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External Disks getting detected only intermittently on 14" MacBook Pro

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