Disk Not Ejected Properly

I've continued to have sporadic problems with this in Sonoma, Sequoia, and Tahoe. I'm not sure I've seen it yet in Golden Gate, but it's harder to know whether it still happens when you're rebooting for an update every two weeks, as sometimes I go a month or more without my Time Machine disk disappearing (whereas other times it happens every day for a week, for no obvious reason).

I used to have terrible problems with this in macOS Sequoia, using a USB hub, or connected directly.
After I switched to an OWC Thunderbolt 4 dock with a really good cable, the problem completely went away. I have a suspicion that OWC is doing something differently than other TB dock makers, but not sure.

On Ventura, I have problems with NVME SSDs on a PCI card, that they will unmount if I read too heavily from the drive. Say, going through large RAW images with Quicklook, or using Smart Folders that return tens of thousands of images, and scrolling through that in icon view.

It has been remarked that the 2023 Apple Silicon Mac Pro, for which NVME storage was really the only use case, coincided with macOS Sonoma, which made these sorts of problems endemic. A full plug-out power cycle is usually the only way to get the system to recognise these drives after they unmount otherwise they're just not there in disk util, etc after a regular reboot.

It has also been remarked, that around the Sonoma era saw the mass storage driver in macOS replaced with an iOS / iPadOS derived version, which never had to deal with PCI *slot* storage, where plug / unplug was not available.

Is this related? My Apple Photos library is on an external WD drive. In fact any external HD drive that contains a Photos library will never eject, it must be forced. My current fix is to first go to Activity, search 'photo', force quit those running, and then eject will perform as normal.

I do not use any photos icloud stuff. It's all unchecked. I use littlesnitch to block all known icloud photo activity. Despite the blocking Apple still 'scan' photos one way or another. I have also stopped using LS and let Apple do what they do, over periods of weeks, the scanning has never ever stopped (in more than 2 decades). All I know is I must force eject (not even a guarantee) or force quit photo activity to eject that external USB HD.

The thing that frustrates me the most is it will tell you the disk can't be ejected because Finder is using it. And then you find out the only thing it's doing is displaying the disk's contents in a window. One of the things I loved about MacOS when I first started using it is it was smart enough not to do stupid things like that. And Windows wasn't. It made me switch

So seeing them regress it that way was a disappointment

@Indigo

The only way I found to stop the photos background processes was to not use the Photos app, and to lock the permissions of the Photos library file in ~/Pictures, so that it couldn't be written / altered.

A library on an external disk should still be usable, because AFAIK external disk-hosted libraries aren't treated the same way as the one in your user directory.

com.apple.photos.migration still runs, but it uses zero resources.

Two comments:

1) Yesterday I was doing a couple-hours long manual process of updating some files. I took a break to eat dinner, and in spite of being told never to sleep when plugged into power, my MacBook Air M2 decided to sleep the monitor after about 10-15 minutes. The monitor contains a USB-C hub, which also slept (probably a monitor bug, but I never told the mac to sleep the monitor - it had been changed by a system update). The HD connected via that hub in the monitor was not ejected properly. It took 3 restarts before I just powered everything down at the power-strip after which I could finally use that drive to finish the task.

2) I have an iPhone SE (2020) which has a battery that's not in great shape. Disconnecting it from the charger would result in the phone dropping 30-40% of its battery in an hour. Removing the Photos app didn't change that, but signing out of iCloud means I can unplug the phone for an hour and now only lose 3-4% of the battery.

Apple's definitely putting the k in kwality lately.

@DavePolaschek Do you use your SE in low power mode? If not, a neat solution is to set up a shortcut automation to switch to low power mode whenever off charge, and then return to normal mode when charging.

One of the main things LPM does, is cut back on background network activity.

Directly attached Samsung Portable T7 SSDs (USB) are very reliable in my experience. I use them as Time Machine destinations on all my Macs. USB cases for NVMEs have been very hit-and-miss for me. One model disconnected every 15 Minutes. Another one from the same vendor stays connected for around two to three weeks between disconnects. Not great, but manageable.

@Daan Yes, the Samsung T7 is the best I’ve found. The one that’s ejecting a lot for me is a Samsung T5, which I got because the T7 wasn’t available in that capacity.