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Sequoia 15.0 bugs - external hard drives

Sequoia update has caused mounting issues with external hard drives. Ex: had one working and then all of a sudden M3 Max MacBook Pro stops recognizing the device. Now, it won't even find it when it's plugged in. Device works fine on other devices.

Posted on Sep 26, 2024 10:10 AM

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Posted on Oct 4, 2024 12:48 PM

This is a USB3 power problem and it's been in Mac OS since Sonoma. I have an M1 MBP and I normally keep an external LaCie dive plugged in to a studio display. Occasionally I take the MacBook on photoshoots and tether to it while simultaneously writing the shots to an external LaCie HDD. Before Sonoma, I never had any problems. After I upgraded to Sonoma the HDD stopped working when plugged directly into the laptop. I took the MacBook and drive to a remote location and suddenly the disk kept randomly disconnecting and disappeared from disk utility when plugged directly into the MBP. When I plugged it into an older MacBook Air with Monterey on it the drive worked perfectly. I connected it the drive to the MBP using a powered USB hub and again, no problems. Sonoma completely screwed up USB power and it sounds like Apple haven't fixed it in Sequoia which is really poor considering there are thousands of reports of this problem. The disk format is irrelevant. Same problems with ExFAT, APFS, MacOS Extended. The only sure fix is to plug the drive in via a powered monitor or USB hub. Just don't get stuck on a photoshoot on a scottish mountain with no mains power and no way of backing up your shots.

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Question marked as Top-ranking reply

Oct 4, 2024 12:48 PM in response to mtnman2152

This is a USB3 power problem and it's been in Mac OS since Sonoma. I have an M1 MBP and I normally keep an external LaCie dive plugged in to a studio display. Occasionally I take the MacBook on photoshoots and tether to it while simultaneously writing the shots to an external LaCie HDD. Before Sonoma, I never had any problems. After I upgraded to Sonoma the HDD stopped working when plugged directly into the laptop. I took the MacBook and drive to a remote location and suddenly the disk kept randomly disconnecting and disappeared from disk utility when plugged directly into the MBP. When I plugged it into an older MacBook Air with Monterey on it the drive worked perfectly. I connected it the drive to the MBP using a powered USB hub and again, no problems. Sonoma completely screwed up USB power and it sounds like Apple haven't fixed it in Sequoia which is really poor considering there are thousands of reports of this problem. The disk format is irrelevant. Same problems with ExFAT, APFS, MacOS Extended. The only sure fix is to plug the drive in via a powered monitor or USB hub. Just don't get stuck on a photoshoot on a scottish mountain with no mains power and no way of backing up your shots.

Oct 22, 2024 4:52 PM in response to mtnman2152

Bad news. I spent several hours at an Apple store yesterday and the outcome isn't pretty. The problem is not Sequoia itself, not power issues, but Sequoia over some previous operating system. I brought to the store 1. my new MBA M2 sequoia, 2. my old MBP Monterey, and 3. my LaCie 8TB drive I'd been using for Time Machine. In the end, they found in the back room a laptop on Seqouia, plugged the drive in...and it mounted no problem. (Apparently this Apple store has kept all their laptops but one on Sonoma. Hmmm.) The best we could come up with is that in all my transitions (2007-2024) from a MB on Leopard to a MBP on Mavericks to a MBP on Mojave to a MBA on Sonoma and now Sequoia, and all the OS updates between, something broke and they don't have a way to find the conflict. Cupertino could fix it. Will they? The only solution I can think of now is to copy all files and applications, wipe my laptop, install Sequoia on the blank laptop, then copy and install all my stuff on the completely new install of Sequoia. Or buy a new desktop drive. Or just use various other drives I have that work to distribute things around. Sitting there in the Apple store with this realization, I felt warmer toward Windows than I have ever felt before. I wish Honda made computers.

Sep 29, 2024 3:24 PM in response to mtnman2152

Last night:

Three drives that work fine on my 2016 MBP (on Monterey: too old to upgrade) are not mounting on my New MBA M2 Sequoia. Two Lacie disks ask permission then don't mount. Lacie 8TB asks permission repeatedly but does not mount. Both Lacie drives are several years old. A Seagate just spins for a while with no recognition. Lacie: 8TB powered HDD and 2TB rugged non-powered HDD; Seagate 2TB pocket HDD.


I used MBP to copy drive to drive. I had problems copying data over from one drive to another bc of old format (wrong format. Reformatted on MBP those drives with problems). All are now APFS case sensitive (to accept old files with case sensitive files). All drives, regardless of age or format, mount with no issues on my MBP Monterey.


Today:

Lacie rugged 2TB mounts in Finder and in DU and identifies as APFS. First Aid runs. Unmounting in Finder does not unmount in DU. Formatted on MBA to APFS case sensitive to see whether that fixes the APFS/Mac Journaled weirdness. As it formats the drive, DU says it's formatting to Mac Journaled. When format is done, DU then identifies the drive as APFS. Lacie 8TB still asks permission over and over and does not mount in DU or in FInder. Seagate unchanged--then tried again; see below.


All problem drives continue to mount without issue on MBP Monterey. Seagate also formats on MBP as Mac Journaled then reports as APFS.


Final state: 2 TB Lacie Rugged works. 8TB Lacie powered asks permission but does not mount in DU or Finder. Seagate now mounts without difficulty--I discovered that the USB cable was not pushed fully in. When formatting the Seagate yet again as APFS on MBA, DU reports it is formatting it as Mac Journaled. When format is complete, DU reports it as APFS.


All drives were plugged every time directly into both MBP and MBA. Seagate uses a USB A to USB C adapter. All others are USB C. Somewhere in this mess I followed Apple support instructions to upgrade from Sonoma to Sequoia. But whatever problems I was having on Sequoia happened on Sonoma as well.


Clearly Drive age is a factor. Both the 8TB and 2TB Lacie drives are at least five years old. Seagate is probably older. Power also a factor as the Seagate that mounted in MBP but did not in MBA was only half plugged in at the drive end. When fully plugged in, it mounted immediately.


I'd like to have all of them work, since they do actually work, just not with this MBA on Sequoia. The 8TB is my TM drive. Having just spent over $1k on a MBA, I don't want to buy a new desk drive as well.



Nov 16, 2024 11:57 AM in response to mtnman2152

Unfortunately, I learned about this issue all too late. I had attempted to let apple sync my music and realized the company was deleting my files from my computer. I tried to restore everything to no avail and my backup has been corrupted and is inaccessible. Now, trying to restore music with my CDs and my external CDROM drive does not work. Fantastic. Thanks, Apple...

Oct 3, 2024 11:33 PM in response to mtnman2152

I have a new external hard drive which is formatted in the format which only works on mac computers (I can't check what the format is as its not appearing in disk utility or finder)


Is the best option just to downgrade from Sequoia? or will an update be released quite quickly? I have very important data stored on this drive.

Sequoia 15.0 bugs - external hard drives

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