Big Sur Disconnecting My External HDD

I have bought a more recent hub and my connection problems have stopped.

I am running 11.1 and still being the problem.

It happens the Time Machine is off.

I thought the USB power was being turned off when in sleep mode (new in Big Sur). However, when I use Option-Command-Eject or Menu > Apple > Sleep the disk stays spinning. I have not left it sleeping for long.

I unchecked "Put hard disks to sleep when possible" Energy Saver.

I opened a Bug Report with Apple.

DISK NOT EJECTED PROPERLY - when Energy Saver setting not to sleep. :(

With Energy Saver settings: x o x o x (no sleep) I ran Jan 9-21 without an EJECT.

I then enabled sleep and it EJECTED on the first sleep.

I set Energy Saver settings: x o x o x (no sleep) and ran 5 days with a EJECT.

However, I did have en EJECT last night with sleep disabled. :( Disabling Sleep appeared to fix the problem until now.

Going to restart with sleep disabled and see what happens.

Just to add some context here: until I got my OWC Thunderbolt hub, every single drive (of all manufacturers I have) was having this behavior. And this is a new M1 Mini with their latest os...no additional things.

No wonder Apple can't figure this out. I reinstalled Big Sur over the existing install yesterday around 1:00 PM. I think the only thing I did different was leaving the drive connected directly to the Mac Mini during the process (same bus as the eGPU). I didn't expect to make any progress, but I guess "never say never" actually has some merit. It's been more than 26 hours and not a single disconnect.

The only thing that makes any sense at this point is that the reinstall did something different because the drive was connected during the install, but even that theory has a flaw... When I did the initial upgrade from Catalina to Big Sur, the drive connected, although at that time the SSD was connected to the dock. Who knows... Apple certainly didn't.

I'm keeping my fingers crossed.

Running into this issue now on my new MacBook Air with M1 chip.

Big Sur 11.5.2

MacBook Air is connected to CalDigit Hub with Thunderbolt cable.

500gb hard drive in unpowered enclosure attached via USB A to hub

4tb hard drive in powered enclosure attached via USB A to hub

So.....no drive is actually powered by the MacBook Air

Every time I return to my desk after the MacBook Air has gone to sleep the external drives are disconnected.

This has never happened with any of my previous MacBooks from Catalina on back.

Just changed settings on power adapter to 1) prevent computer from sleeping automatically and 2) not put hard disks to sleep. I'll see if that makes a difference.

Is that a real disconnect or the does the icon just disappear?

I have the same issue after updating to 11.2. Mac Mini ejects RAID created with Apple Disk Utility. It doesn't eject my other USB external and runs fine on my other Mac Mini running 10.5.

I have a Mac mini 2018 and 3 external hard drives connected. All of them are encrypted. Connection of 2 of them is over USB-C to USB-2 adapter and the third one directly from a USB-2 outlet. I have no problem with that, and the computer can go to sleep without the drives disconnecting. One of them is not a time machine.

To those who have still have the problem, does the problem also occur with a simple USB stick?

You may wanna sell it then, this issue has been open since day 1, I solved it by using a specific thunderbolt hub (which I needed anyway, but it hadn't arrived when I was originally encountering the issue). You can call Apple if you want, maybe that will make a difference, but given how many people continue to complain about this, I don't think they're ready to listen. Must need more people :/

I am having this problem too. It is happening on a new MacBook Pro, M1 chip, purchased in December, running 11.1. I have two other MacBook Pros, the first running 10.13.6 (late 2011 model), and the second also running 11.1, purchased in June 2020 (Intel chip), and the problem does not occur with either of these computers, with the same external drives. I wonder if it is a hardware issue? I'll be putting a call into Apple when I have time, I'll report anything useful back.

I continue to have this issue no matter what I have done to avoid it. I am going to try adjusting my settings to never let the computer go to sleep, I am running the M1 Mac mini, and will report back in a few days. The amount of times I come back into my office to find my external HDD enclosure powered off is unacceptable. If this doesn't work, I'll resort to contacting Apple directly, though I am unsure what that will solve, as the issue is random and not user repeatable...

I ran without DISK NOT EJECTED PROPERLY from Jan 9th to Jan 21st.

I disabled "Prevent computer from sleeping automatically when the display is off"

and the disk EJECTED during the first automatic sleep.

There may be other factors, but for me, the HDD used for TimeMachine, will spontaneously NOT EJECTED PROPERLY when the machine goes to sleep.

Folks, if it wasn't obvious (it looks like my uploaded screen-shot isn't visible...), at its worst I see the message pop up as frequently as every minute-or-two while I'm actively using my Mini (meaning: the Mac is not going to sleep, and sleep has nothing to do with the problem (at least in my case).

Yep, you got the same issues as many of us are having, I have found it's often easier to just reboot than to try to clear all the messages. Also, if you just let this go on for a day or so, I've found Finder is hung and you have to reboot to get the machine to respond without being super sluggish waiting on I/O operations (e.g. use the "Open.." option on apps and attempt to open a file)