External SSD Disconnects Repeatedly Mac Mini M1 (Big Sur)

I can't believe that this is still going on, after a year!

I have a ThunderBay 4 that behaved perfectly for 2 years with my Mac mini Intel.

I just replaced it with a new Mac mini M1, and now I experience two variations:

• the common “not properly ejected” warnings
• the drives going to sleep even though the Energy Save box is unchecked for “put hard disks to sleep”.

The cable is an OWC T4 cable. The macOS is the latest Big Sur.

There are a thousand postings about this — from Reddit to StackExchange to Apple Support — but I see no answers.

Could it be that Apple has been ejected? Put to sleep?

I'm having the same issue. Mini M1, 256GB, 16GB memory, Big Sur 11.1

I have two external drives, one 500GB HDD in a bus-powered enclosure and the other a 1TB HDD in self powered enclosure. Both are set up as Time Machine backup drives and will randomly, separately, repeatedly and inexplicably cause "Disk Not Ejected Properly" warnings. As long as they are plugged in, they will reappear on the desktop - even if I properly eject them. Sometimes hours will pass without the issue, but then it occurs. Seems not to have any ill effects that I've noticed.

I can't correlate this symptom to anything specific. I have switched ports, cables, etc. but seems to make no difference. Both drives and cables have been used on a previous Mac without issues and I have run First Aid as well without issues.

Maybe it has something to do with Time Machine. I have another external drive that I use for non-system file storage (music, photos, documents, etc.) and it has never had this issue.

Hopefully, there will be a reason and solution?

I think my issue is resolved. Its been a couple of weeks with no disconnects due, I believe, to de-selecting "Put Hard Drives to Sleep" under System Preferences/Energy Saver selections. I was reading elsewhere that some people were having different sleep/wake issues, so thought I'd try this selection to see if it would make a difference, and it seems to be the answer so far.

Sleeping HDD was never a problem with Catalina on my old iMac (even though using SSD), so I didn't think it would be any different with Big Sur and M1 Mini (and it doesn't affect the Mini's SSD), but apparently it may* be the cause of the disconnects I was having with external drives.

*I will report if the problem recurs.

Solved for me:

I had this problem constantly on my 2020 Mac M1 Mini. This same SSD was plugged into my Windows laptop problem free for a year. Often when idle but also at other times, the popup of disk ejected improperly would come up. I disabled power saving, I ran an app to keep it alive, nothing was working. Then I bought a super short thunderbolt 3 cable and I have not had a problem since, it has been nearly a week.

I had even bought an expensive Caldigit Elements powered thunderbolt 4 hub and the problem had been coming up, it only went away with this cable swap.

Hopefully this helps someone as the problem is incredibly annoying!

Adam

I think it is an Apple problem and they will not admit it. It has happened to me several times on both Mac mini and Macbook Air m1

Hi there dschommer,

Thanks for using Apple Support Communities. It sounds like you have an external drive disconnecting when trying to write some files to the drive. Since this issue does not occur when using a different connection method, it may be the port or cord you are using. Check the port for any debris and try replacing the thunderbolt cord.

Try repairing the disk in Disk Utility as well. See how here: Repair a storage device in Disk Utility on Mac.

We hope this helps!

ckbarlow wrote:

@IdrisSeabright

Regardless, the ports need to work.

If you're having a hardware issue, I'd suggest contacting Apple and arranging to have them evaluate your computer. Some of the diagnostics can be run remotely.

Genius Bar Reservation and Apple Support Options - Apple

To your questions:

1. No, it is not limited to one OS or to M1 Macs. I have been experiencing this issue since upgrading to Catalina on a 2018 MacBook Pro 13" with Touchbar.
2. I don't know. For me, it has mostly happened with an external SSD connected directly, but it also happened when I connected the same SSD through an OWC hub that I sent back (because it didn't solve this issue). It also happened with another disk, a traditional HDD, the other day for the first time. The SSD was also connected at that time.
3. I have used chat to start and document the conversation, and they have had someone higher in the chain call me back to discuss.

Here's how I solved my similar issue:

• By NOT having any software (either a document file, or an app itself) running from the external drive. Specifically, don't open a stored document file on the external drive and leave it open for a long time (say overnight), even if the app itself is running on the local drive.

My example:

2020 M1 Mac Mini (256GB/16GB) Big Sur

4TB Seagate 2.5" External Drive (unpowered, plugged directly into USB-C/TB port) ie. no hub

Energy Saver - everything set to "off/never"

Running Plex Server on the local drive

Movie files stored on the external drive

At first I thought the Disk Eject error it was completely random. But I eventually noticed that whenever I played a movie from my external drive at night (through my Plex server setup), the next morning I'd awake to the dreaded "Disk Ejected Improperly" error message. Even though the Mac Mini was in another room, clearly untouched - but left on overnight. Mind you, took me while to notice the connection - as the message didn't show up right away.

This eventually wrecked the drive too. So for my new drive, I just ejected the disk after each use. Not ideal, but no error messages showed up anymore either. However, it was oddly tricky to eject the drive properly (even with Plex turned off beforehand). By right-clicking eject, the drive icon would indeed disappear as normal... but if I waited (... 20 seconds?), the icon would mysteriously reappear again. wth? Ejecting it a second time did the the trick though, for good. Weird.

Once I figured this out, I was able to replicate the process and error message over and over again, even using other software/files I had, not just Plex.

Is it possible that this glitch is due to some combination of open apps (and/or files) and the external drive ignoring MacOS sleep instructions? I suspect it's disconnecting (or sleeping?) on its own, as the drive light is off when the error message finally shows up. If the light is on though, no eject errors.

FWIW

I have a LG UltraFine TB3 5K monitor and a Nestor TB3 NVME SSD enclosure with a 2TB Samsung 970 Evo Plus SSD on my M1 Mac Mini (8GB/512GB). I first had the Nestor daisy chained off the LG Monitor on the right (from back) TB4 port. Things seem to work well. Then I ran some Black Magic speed tests and noticed I was only getting 800GB/s writes when it should be able to go much faster. I shuffled connections, put the Nestor alone on the left TB4 port and kept the monitor on the right port. With the Nestor on it's own port, I got 1300+GB/s writes - not a bad speed bump for just a reconfiguration. But then over the next couple of days I started to experience random disconnects of the SSD, not tied to any particular application or action. I have my photos library on the SSD so it does get accessed by background processes quite often. I started wondering if the Nestor was failing but then remembered the reconfigure. This morning as a test, I swapped ports, monitor on the left, Nestor on the right. Same speed and so far, none of the disconnects (and I had had two in 15 minutes before swapping ports.)

Seems like between bluetooth and TB, there are some bugs to be worked out. Hope 11.2 makes improvements.

dschommer wrote:

Has anyone had an issue with your external SSD's on Thunderbolt (and a few times on USB3) just randomly disconnecting? It disconnects and reconnects instantly and comes back online after tossing a notification not to disconnect a drive without hitting eject.

This was an issue with some drives requiring too much voltage for the port, but I've only seen it happen to HDDs, not SSDs.

Which SSD (specifically) are you using?