Unable to access External Drives and Disk Utility after updating to macOS Sonoma.

Using an active USB hub did the trick for me.

I purchased a TP-Link UH720 USB 3.0 hub which is an active hub, meaning you have to plug it into the power socket too. Then I used a USB 3.0 to USB-C adapter cable and it works. macOS sees all my external SSD drives just as before the Sonoma update.

Nonetheless, this is still infuriating from Apple.

Not sure this is helpful to anyone, but what worked for me (Lacie usb-c spin-drive, Journaled) was to simply replace the usb-c cable. I´m no expert by any means, but suppose these cables have different voltage capacity, bandwith or something. The previous two cables would allow the drive to show up in the Finder but wouldn´t allow me to either view or access any files.

Strangely enough, when connecting the drive directly to my iPhone 15 Pro Max, any usb-c cable worked without issue and the files showed up immediately?

Moving all files to the laptop then I´ll convert the external drive file system to APFS, which seems to be a general

recommendation when not using the drive across different platforms.

All my disks now are readable however I still cannot update my Photos library which is in ExFat - I receive there was an error attempting to free up disk space for import. I'll wait 2 more months then maybe resell his M3 Macbook air.

annabellerama wrote:

So what is everyone doing when their external drives and Time Machine backups are no longer available??

*I need to know because that is exactly the situation I am in…

I’d verify my other backups and then erase the bad drive and try it again.

I have an Mac Studio with Sonoma and my SanDisk Professional Thunderbolt 2TB SSD for video production that was formated exFAT and had all the same issues mentioned here. (Was just glad I had a PC with thunderbolt to repair the drive and get my data off).

Since I really only needed this drive on my Mac, I then formated it APFS. Now it will lock up the finder if it is connected for more then 20 min. Once this happens, using force quit to relaunch the finder only shuts the finder down without relaunching it, making it hang on shutdown or restart. So now the only fix has been to hard power down holding the power button. Once it reboots, it all works again. I can now use the drive, but I can only use it to transfer files quick and eject it before it freezes my finder once again.

This seems like a bigger issue then just exFAT, I have been having all kinds of quirky issues with any wired peripherals since Sonoma (like a Blackmagic Ultra Studio only being recognized 50% of time when connected via thunderbolt USB-C).

The thing that bothers me the most is that until Sonoma, if there were big issues like this (and this is BIG) that hinder businesses from working with Apple products, Apple would be on top of it and have a fix fairly quickly. But when I talk with Apple, it is like they have no idea there are any issues. I mean, if we are all having this problem, it would make sense that the employees at Apple (at least some of them) must be having these issues also. It is just the lack of acknowledgment that is odd.

Right there with you raine212 w/ respect to photography and videos. Photos/movies

saved to several external hard drives, NONE of which will mount. Have to use older MacBook High Sierra which really sucks, b/c I know it will crash and burn soon (i.e. internet links already crashing). My new MacBook Pro Sonoma, 14.4.1, cannot be restored to a version it never had in the first place, so am screwed no matter what.

Apple and Apple Support, FIND AND RESOLVE THIS ISSUE.

[Edited by Moderator]

Thanks for the suggestion. I have a 2023 Mac Mini M2. I have experienced Sonoma fails twice and my Sonoma fix, both times required a clean install of Ventura 13.6.3. Then the external connections worked again. With the exception of one problem, now the external USB-C 2-T NVMe drive will not shut off when I shut down my Mac. The drive gets hot and will finally shut off after several minutes. Before attempting the Sonoma upgrade, this problem did not exist. Some desktop Macs do not have the "Allow accessories to connect" option that began on Macbooks with Ventura (see https://discussions.apple.com/thread/254478957?sortBy=best for more on this issue) Since I dont have the courage to endure another Sonoma fail to see if this works for my Mac Mini, I am interested to hear if other users with a desktop Mac running Sonoma have the "Allow accessories to connect" option available?

I've been testing a Kensington 960GB HyperX SSD connected with an Apricorn SATA to USB3 dongle and a USB-A to -C adaptor. I have tried everything mentioned here to corrupt the drive and I cannot.

The only thing I haven't done is pull it out while writing.

I've left it connected when I shut down.

I've just pulled it out of the Mac without ejecting.

I've written large and small files.

I open, edit and save the files.

I copy new files to the drive and edit them.

I play audio and video files from the drive. I haven't edited them as I don't normally do that. If people do that on them, what software do you use?

I am using a M2 Pro MacBook Pro running current versions of Sonoma.

I would love to file a bug report for this, but I cannot manage to replicate the problem. Does anyone have any other ideas of what I should be doing with the drive that is different than what I have listed?

Possibilities:

• Type of files
• Applications
• Drive utilities

I don't have any other SSDs to test.

Perhaps it is related to the controllers. Has anyone noted any particular make/model drives that are being corrupted?

The solution with the brand-new lacie rugged, 4 TB external was to;

1. delete and remove the “useless seagate” tool kit.

1. With apple utilities , partition the drive in to 2 partitions. It would not allow me to just directly erase and reformat in to APFS.

3 Now I could erase and reformat the new partition into any APFS.

4 restarted computer

5 now I could erase and format other portion too.

6 restarted and merged the two partitions.

7 erased and reformatted the partition again into APFS encrypted.

No logic but now it mounts and works as it should.

no more disappearing files… it seems

🤞

• Your post states in Item 2 "Sonoma may be finicky on your machine"

My machine is a low cost 2023 Macmini M2, 256g internal and 8g of RAM, that has a 2T SSD external drive plugged into usb-C/thunderbolt 4 port, formatted day 1 APFS, that worked perfect with Ventura, the origianl installed OS. Updating to Sonoma 14.2.1 put a quick end to this happy situation. After many hours of frustration over several days, I went full WOKE and "cancelled" Sonoma! Restored via a clean install Ventura then Time Machine restored back to wonderfully functional state of bliss I previously enjoyed. Sonoma is dead to me. BTW, I can't find any compelling reason for Sonoma to be worth the bother. To accept from the talking heads at Apple support the explanation that, as you state, "Sonoma may be finicky on your machine" makes my head feel like exploding. W. T. F.? Apple support? Give me a break! Shame on you all!

I have a pretty much state of the art 2023 Mac Mini M2 8G ram, 256 internal, and a 2T external SSD FORMATTED in APFS since day 1. The computer came with Ventura installed and the SSD worked perfect! Then I recently migrated to Sonoma 14.2.1 and the external ssd drive disappeared after rebooting, never to be seen again by Sonoma.

I tried all the tricks and still no external ssd to be found. 

It is an outrage that the recent update Sonoma 14.3 does not correct this critical flaw!

Out of frustration, I concluded that Sonoma sucks and I restored Ventura as follows:

On a Mac with Apple silicon your computer must be connected to the internet. If you’re reinstalling on a Mac laptop, plug in the power adapter.

1. Shut Down your Mac, press and hold the power button until “Loading startup options” appears, select Options, click Continue, then use Disk Utility in the Recovery Window to initialize your drive APFS, which wipes it clean.
2. Then, In the Recovery app window, select Reinstall for your macOS release, click Continue, then follow the onscreen instructions. 

After I reinstalled Ventura, I restored the most recent Time Machine backup, which was only 2 days old. Being very grateful that all my precious data had not been chewed up and destroyed by Sonoma as some have reported happened to their external drives data. Did I mention that my Time Machine is on the external SSD?

I’m happy to be back with Ventura. For me, there is absolutely nothing compelling about Sonoma that warrants having to put up with any hassles with it. 

[Edited by Moderator]

So it looks like ExFAT formats can't be read by Sonoma ? What a shame. I guess one must use USB Fobs now to transfer between Macs and Windows then.

Did APFS resolve your issue?

Barney-15E, I just noticed that copying a large file to a ExFAT formatted drive takes 4x longer than if the drive is formatted to APFS. Have you seen this issue? Just started with Sonoma.