I have several LaCie 4TB drives. After installing Tahoe, they no longer boot. Disk Utility displays them, but nothing works to get them to appear on the desktop. Have also run Disk Utility on the main internal hard drive, but it found nothing. Running on a Mac Studio M1 Max.
Mac Studio (2022)
Submit bug reports here:
I have connected half a dozen Samsung SSDs over the past couple of days on my M4 Pro MBP, running Tahoe without issue, and various shares on my NAS mount fine.
One thing to try is booting in Safe Mode, in case you have 3rd party extensions causing an issue.
warner505, that's interesting to hear that. I know how it feels...
I have just posted a similar question about an external Lacie drive dismounting in sequoia 15.7. This is also the only spinning drive I have that is formatted in APFS. None of my HFS+ formatted spinning drive RAIDS are having issues. In my case, a new Lacie 2 Big Dock is dismounting in 15.7 but my old ones are working fine. To add to the confusion, all my external drives seem to mount OK in Tahoe using an external boot SSD. But I want to test that over a longer time frame before proceeding with Tahoe, or wait for the first revision to arrive.
Can I ask:
How many of your Lacie drives are APFS formatted?
How many of your drives contain Time Machine backups?
Have you tried a safe boot or a ‘test’ account yet?
Your not alone. Apple has not said anything about this issue. I do think they will try to make it go away quietly with an update. I have some nice gear from OWC and Micron. These drives experienced file structure corruption after Tahoe upgrade preventing them from mounting. Apple has been solid with their file systems in the past, but this has shaken my confidence. I follow 123 backup policy, but I still lost days sorting out what went wrong at 1 Infinite Loop.
Same here. 2023 MacMini just upgraded to Tahoe. Worked fine before. SanDisk Professional external drive, formatted APFS, shows up in Disk Utility but will not show on desktop or on sidebar and yes they are both checked in Finder. Computer SSD does show on desktop but will not show in sidebar. Nothing shows in "Locations". Frustrating to know it's booted but I can't access my data. I do have back ups, but I'm doubting they're going to show either.
Addendum: Tried unmounting via Disk Utility and remounting via same. Both seemed to work, but nothing shows in finder. Additionally, it is an encrypted APFS volume, in case that is significant
Confirm Finder menu > Settings:
That's good advice (I hadn't thought of it), but "External disks" is, indeed, checked.
I noticed that on some occasions after installing Tahoe, the external drives would mount briefly (though they couldn't be accessed), and then would disappear with the "not properly ejected" warning. Sometimes, I used a USB hub, and sometimes I plugged the drive directly into the Mac — and received the warning in both cases.
This is happening with four LaCie drives and one Seagate drive. The drives are appearing correctly on a laptop that hasn't been updated with Tahoe.
Installed mac today with Tahoe 26 and yes drives and discs not recognised is this someway for us to buy new stuff have always been a loyal mac user with phone i mac and pad but now starting to wonder if i wqs correct in updating to this latest software have tried all the info given out but now thinking can i go back
Yes same here with a 4TB partitioned and been used for just under a year, I know its reading, through it on to a windows machine and can see its partitions, but obviously cant read the files, I know something major would stop working, wish they would stop using us as guinea pigs !!!
Any advise would be amazing, just hope apple tech jump on this pronto, thinking Lacie was the way forward
Thanks, man. Will do.
Anyone else having an issue where external drives no longer appear after installing Tahoe?
