Sequoia 15.0 bugs - external hard drives

Glad to know it’s not just me! Since Sequoia, I can’t access my photos on my external hard drive! I don’t know what to do because I need to make a video for my daughter’s wedding in Final Cut Pro X!!!

APPLE DO SOMETHING!

Maggot wrote:

I want to add my voice to this.

Since updating to Sequoia in November, 2024, neither of my external USB-C drives have functioned normally: spontaneously unmounting; Photos (my library lives on an external drive) having to quit, rebuild or restore from iCloud; Time Machine backups via USB-C taking FOUR HOURS to complete, even when no files have been changed or added.

But the kicker is that since these problems began in December I've had EIGHT kernal panics, including three in the last 24 hours. I thought it might be an incompatability issue with the external drives' HFS+ journaled extended file systems vs. APFS, so I chucked five years of Time Machine backups, and erased and reformattted the Time Machine drive to to APFS—and halfway through the first backup the process simply quit, and then crashed my iMac simultaneously, too.

I've run Diagnositcs ("No issues found"), and started up in Safe mode. I've reset the SMC and zapped the PRAM. I ran EtreCheck, and it was clean. The only thing I can think of is that something is causing the OS to not play properly with USB-C. (FYI, the drives are both G Tech G-Drive mobile, 2TB and 4TB.) I've unmounted and put both drives aside to see if the panics continue.

I'm currently backing up—flawlessly—to an ancient Seagate USB 2.0 drive. I can't be sure, of course, but it seems that USB-C is the culprit.

iMac, late 2020 (last Intel model)

Sequoia 15.2

32G RAM

I think it is a power issue. My Mac Mini M4 doesn't have any legacy ports. They are all USB-C/Thunderbolt 4. So even my LaCie 1TB external drive, which I have to connect via a non-powered hub also sometimes disconnects, although not as often as my USB-C drive.

I am going to try a powered hub next and see if that helps but honestly, 2025 and Apple can't sort this out? Crazy!

A knock wood update:

Since I decomissioned both of my USB-C external drives (one exclusively for Photos, the other for Time Machine backups), I haven't had any kernal panics. None.

As I mentioned above, I am currently using an old Seagate USB 2.0 drive to do Time Machine's dirty work. It backs up hourly with no issues, and in under a minute and a half generally. In other words, it works.

This is, in my opinion, Apple's buggy implementation of USB-C in Sequoia/Sonoma. (Upon reflection, the Time Machine backups taking way too long may have begun in Sonoma.) Likely a software implementation issue, in my opinion. They need to fix this ASAP. (And yes, I have reported the issue to Apple.)

Running 2023 Studio M2. Things were working great until I "upgraded" to Suckquioa.

Now, my powered Insignia hub isn't recognized. I need a hub because I use multiple flash drives at the same time for my work. More importantly, I also need more because one of the USB ports is being used by my husband's pacemaker monitor. Because my hub isn't recognized any more, that monitor must be plugged into one of the Studio's ports directly.

If this IS a KNOWN issue with Apple, WHY the bloody .... are they not fixing it??? My case isn't just a work thing. It could mean a BIG issue with my husband's heart!

I've been troubleshooting this, and here's what I've found. (On a Mac mini M4, running Sequoia 15.2; Mediasonic Probox enclosure with 4 bays housing spinning drives and an SSD. Everything stopped working sometime between 15.0 and 15.1.1)

If I run my Probox (JBOD) with just one SSD, it mounts just fine. The moment I add an HDD, everything goes belly-up. Since this is a wall-powered unit, clearly it is not the power drawn that is the problem. I had suspected the interface with the Probox being incompatible with something in Apple's new hardware implementation, but that is now ruled out. What remains is clearly the older drives themselves.

I also have a Seagate 2.5" Expansion HDD which is mounting when connected (it's another matter that the disk is terminally ill). But other 2.5's do not mount when in the Probox, so I don't really know what to make of this bit of info.

What I find curious is the inconsistency of behaviours. In my case on a Mac Mini M4 Pro, I’m only having troubles with USB-B 2.5” external hard drives, a WD My Passport 5TB in particular. After a reboot, it usually doesn’t appear let alone mount. Disk Utility just spins looking for drives. Sometimes, if I just get on with my activities, then after random lengths of time it just appears on the desktop. I have 3 external USB-C SSD drives and these don’t exhibit any issues at all. I’ve tried powered hubs but that makes no difference. The drives are formatted ExFat and if I plug them into my old Windows laptop, they appear straightaway. Sometimes I get a message that there’s an error on the drive and asked to run error checking and repair. I do that but then get a message no errors were found. If I take it back to my Mac, it mounts immediately but then later returns to not mounting. I’ve been using external drives for years for photo storage and backups without issues. This has only started to be a problem on the MM which came with 15.1 installed. Failing any other explanation, it does seem to be a Sequoia caused problem to me. But why is it so different for various users?

Maggot wrote:

I want to add my voice to this.

Since updating to Sequoia in November, 2024, neither of my external USB-C drives have functioned normally: spontaneously unmounting; Photos (my library lives on an external drive) having to quit, rebuild or restore from iCloud; Time Machine backups via USB-C taking FOUR HOURS to complete, even when no files have been changed or added.

But the kicker is that since these problems began in December I've had EIGHT kernal panics, including three in the last 24 hours. I thought it might be an incompatability issue with the external drives' HFS+ journaled extended file systems vs. APFS, so I chucked five years of Time Machine backups, and erased and reformattted the Time Machine drive to to APFS—and halfway through the first backup the process simply quit, and then crashed my iMac simultaneously, too.

I've run Diagnositcs ("No issues found"), and started up in Safe mode. I've reset the SMC and zapped the PRAM. I ran EtreCheck, and it was clean. The only thing I can think of is that something is causing the OS to not play properly with USB-C. (FYI, the drives are both G Tech G-Drive mobile, 2TB and 4TB.) I've unmounted and put both drives aside to see if the panics continue.

I'm currently backing up—flawlessly—to an ancient Seagate USB 2.0 drive. I can't be sure, of course, but it seems that USB-C is the culprit.

iMac, late 2020 (last Intel model)

Sequoia 15.2

32G RAM

Update #2:

My iMac hasn't had a kernal panic since I disconnected the two G Drive mobile externals. Prior to disconnecting them, on January 10th, I had three panics in one day. So something's definitely amiss there. But glad that the panics have stopped.

I installed 15.3 yesterday, hoping it may solve my issues. I connected the G Drive with Photos on it, but this time using the (included, OEM) USB-A to USB-C cable. Everything worked fine until about an hour in, when I noticed a bit of lag when scrolling through photos. After leaving the iMac for about an hour, I got s familiar message: "Photos has to quit" or something to that effect. I disconnected.

I told the senior Apple support person that I'd wait until 15.3 to try anythoing further, so I guess it's time to get on that merry go 'round again. Frankly, I'm thinking this will be a complete waste of my time. I think they've somehow broken the USB-C implementation at the OS level, and since it manifests differently across machines, but not globally, they're not all that concerned about fixing it.

We'll see. The alternative: both my USB-C drives somehow simultaneously reacted to the install in a bizarre manner. Seems a stretch.

I have had USB-C external drive connection issues since, at least, Sonoma, I am thinking as far back as Monterey. Disk Utility, Time Machine and other software have, at times, been unstable or virtually useless.

Now, since Apple Intelligence was released, CleanMyMac X fails to complete exhaustive scans, apparently because Spotlight (or its associated utility software) is constantly indexing my internal and single external (Time Machine) SSDs.

Time Machine sets that off as far as I can tell. Every hour, Time Machine backs up my 2021 M1 iMac, which sets off more indexing.

So it never stops, at times, radically slowing my system down and interfering with software performance and I/O while consuming memory as well.

I believe Apple knows about this and either can’t or won’t resolve the USB-C issues on M series Mac’s.

There seems to be hundreds of people mentioning similar and likely related issues on these forums as well.

Good luck.

I've been dealing with endless external hard drive issues, and my drives are kept safe in their shipping box and only backed up occasionally. I have two HD drives. IN November an 11 months old Lacie Rugged 2T that had hardly been used could not be "mounted" and would not show up on desktop. Called Apple, they said it was Disk problem. Called Seagate they said it was Apple problem. Went to Genius bar they treid different cables etc, and said it was definitely disk. Sent disk off to Seagate and it was returned. Data Recovery rcovered about 500 mB of a 188GB of data.

Anyway long story short the several Seagate reps I spoke with said they are increasingly seeing Disks malfunctioning since Sequoia updates (which is when mine stopped working.) My bet is on the Sequoia update. I've also had a whole folder on my "deceased father" just "disappear" from my desktop over night, Apple couldn't find it, and it wasn't even in my Icloud storage less than 12 hours after I'd last opened it. It has just gone poof. Althought word and excel files were still traced if i checked "recent" in my microsoft software, but couldn't be opened as it said there was an error or file had been deleted. Absolutely no idea how any of this happens. I"ve had Macs since 1990 but i can only say that since 2016, they've become increasingly buggy. I'm going to tough it out with the older macs for as long as I can. As the new macs and the software updates seem to be increasingly "buggy" as for the "iCloud" drive well no idea how a file goes AWOL from both within 12 hours of me using.

Apple is not what it used to be. I have a samsung phone, and will never by an Iphone, as people have same issues. Samsung cameras might not be as good, but the phones themselves are much hardier.

Todate I'd say Sequoia has been a disaster, and apple are just trying to cover it up. My take.

Same. But after updating to 15.3 my external hard drives don't show up at all. They will trigger applications, but won't even show in Disk Utilities. The main hard drive won't show there either when an external drive is plugged in. When I disconnect the external drive it gives me an error that the disk "can't be unlocked".

When trying to resuscitate lost drives, I can recommend popular at home rescue programs can be useful to keep the drive mounted while you drag files onto your desktop to retrieve them and/or rescue files. Had less success with bringing drives to 'pro' disk rescue services who were charging well over $1400 to say that once they got to the info on my most important lost drive, that the drive ate itself - and all the info on it. They returned it w/o success or charge along with another drive that I was able to mount on my computer using a full-feature data rescue program. Going forward, make sure to purchase drives with multi-year rescue coverage built in. That has been a good backup while experiencing this problem since 2022.

As for resuscitating drives, my fix has been to run the drive through Check Disk tool on my Windows laptop. Fixes whatever errors are on the drive. Of course this only works on FAT or NTFS, eg ExFat drives, which is what my problem drive is formatted.

I had success ejecting the drive after using AI (Grok) to troubleshoot. Not sure if this is all the issue is but I was able to kill the PID by using terminal commands to get my EHD to eject. This is the process that helped me:

1. Check for Hidden Processes with lsof:

• Open Terminal again.

• Type: sudo lsof | grep /Volumes/DRIVENAME (replace DRIVENAME with the exact name of your external drive as it appears in Finder).

• Enter your admin password when prompted.

• This lists any open files or processes using the drive. If something shows up (e.g., a random app or system process), note the process name or ID (PID), then quit it with sudo kill -9 PID (replace PID with the number).

• Try ejecting again after.

2. Force Unmount:

• If diskutil eject didn’t work earlier, try forcing the unmount:

• In Terminal, type: diskutil unmount force /Volumes/DRIVENAME (again, use the exact drive name).

• This is a stronger nudge than the regular unmount and might override whatever’s locking it.

3. Spotlight or Time Machine Interference:

• If the drive’s being indexed or backed up, macOS can be sneaky about it.

• Disable Spotlight temporarily:

• Go to System Settings > Siri & Spotlight > Spotlight Privacy, drag your external drive into the “Prevent Spotlight from searching” list, and click “Done.” Wait a moment, then try ejecting.

• Check Time Machine:

• System Settings > Time Machine—if it’s mid-backup, pause or skip it, then eject.

After reformatting my two Time Machine externals, both are working now. Strangely, the crashing of my Photos external drive (Mac OS Extended Journaled), which I decided not to reformat, has also stopped.

That said, the Photos external can't be ejected because some "processes are in use" or something to that effect.

But no more kernal panics or constantly crashing apps. I can live with this.

Since your problem is totally different from the Authors you should start your own topic with details of your Mac, system, drive, etc . as described in this Apple document: Writing an Effective Apple Support Communities Question - Apple Community

That will get responses from those who will be more familiar with that problem then those coming here.