Disk not ejected properly

I have a Mac Mini M2 with the same issue, my external disk gets ejected randomly.

Tried the "usual" tricks plus going to Ventura Beta and changing the disksleep, it didn't work for me.

Disk is fine and worked flawlessly for 2 years with Windows PC.

Reformatted the disk to APFS for the Mini M2 and started getting this issue.

With the Mini the disk gets ejected randomly when connected directly to either TB or USB ports.

But if I connect the disk via generic USB hub to Mac Mini usb port the issue does not manifest itself, tried both USB2 and USB3 ports on the hub, also connecting the hub via another hub, and still works fine.

On another forum it was suggested this might be a current issue, too much current being drawn.

Just my 2 cents.

I have the same issue. Any clue how to fix it?

I'm having this problem after I "upgraded" to the M1 Pro MacBook Pro. The disks got randomly ejected like crazy. It almost always got ejected after been woken up from sleep, and sometimes ejects itself even if I'm actively using it (like copying files). I'm 100% certain my disks / cables are not the culprit because I still use them on my old Intel Mac and they work flawlessly. I think this is some hardware driver issue (maybe insufficient current? I have two 5TB external HDDs)

However, after I updated to macOS Ventura 13.4, the issue seem to have been fixed. My two disks are plugged in for a week now without ejecting itself (what a miracle!). I'll need to keep observing to see if this is actually fixed or I'm just somehow getting lucky.

i also have some problem. but the issue is solved when I find which process is accuping the disk. The reason my be that when you get your mac sleeped your mac would try to sleep your disk also.

I have the same issue to use my external 2TB usb disk. My solution is to change to Apple type-c to type-c cable. Instead use USB disk's cable. Everything is fine now. Just for your reference.

Same issue here, but it only happens with one WD external drive. "Disk not ejected properly" message appears about 20 times when I open turn on my work Mac in the morning. Drive is still connected.

Happens on the Mac Mini, and also on my Macbook. Tried 3 different cords, 2 different ports on the Macbook, and 4 different ports on the Mac Mini.

No recent software updates.

So it's not a hardware or software problem on wither computer.

Disk Utility - drive checks out okay.

I'm going to try reformatting the drive next and see what happens.

I have the same issue with a LaCie Rugged 5TB USB-C HDD, and a Mac mini M1 running macOS Sonoma 14.3. I've done a very long investigation with the Apple Support team and Genius Bar, and with Seagate support chat. My findings so far for my issue, in case it's helpful:

• Easy way to reproduce: put the computer to sleep and wait 3 minutes. There should be a popup.
• As someone mentioned, after some days, it may start failing even when working with it. I get a popup every 2 minutes, constant rate. Restarting the Mac fixes this issue (restart in safe mode to restart the NVRAM just in case), and it's back to just failing on sleep.
• It happens with other Macs, on macOS Sonoma. We tried other Macs in the Genius Bar.
• It DOES NOT happen when using a USB-C to USB-A cable.
• It DOES NOT happen when using a 240W thunderbolt charge cable (the £29 cable).
• It does happen when using the expensive (£75) Thunderbolt 4 data cable (100W according to the specs).

I called Apple support again. The engineer explained that when you connect the drive to the computer, there’s a handshake that determines whether to use Thunderbolt, or regular USB-C. Even if the port looks the same, Thunderbolt and USB-C are actually different connections. The Mac must think it’s thunderbolt even if I use a regular USB-C cable. And then it’s when it becomes unstable. When it goes to sleep, it tries to keep a register of the connection so it doesn’t have to do another handshake, or spark a new connection again. Then, when it wakes up it sends data as it was Thunderbolt, when it’s not.

That’s the explanation I got and I was suggested to keep using the 240W thunderbolt charge cable. That doesn’t seem to explain why it didn’t work with the Thunderbolt 4 cable, though.

However, Seagate asked me to do some speed tests with the different cables. If you are doing this, I recommend using a big file to get consistent results. I zipped my local Movies folder, and that gave me a 1GB ZIP file. To test the copying speed from the Mac mini SSD drive to the external drive, I used rsync. You can use it like this (“LaCie 5TB” is the name of my HDD):

rsync -ah --progress ~/Movies.zip /Volumes/LaCie\ 5TB

I tried with the Apple cable I got in the Apple store, and with the original LaCie cable:

• With 240W thunderbolt charge cable: 36.87 Mbytes/sec
• With USB-C to USB-A adapter cable (for reference): 38.21 Mbytes/sec
• With USB-C cable from LaCie: 123.62 Mbytes/sec

So it’s much slower with the charge cable, as slow as using USB-A 😢 But I can’t reliably use the LaCie cable. Or the £75 Thunderbolt 4 data transfer cable. Seagate says the drive is compatible with both Thunderbolt 4 and USB-C. The Mac Mini M1 port is Thunderbolt 3.

Seagate escalated this issue and they told me to wait 24 hours. I will also try to contact Apple again, because I'd really like to use the faster speeds.

I have several disk not ejecting properly, while using Amphetamine or similar to write down every 100ms (further wont work) and keep the disk alive works, I found out that formating the disk again makes the disk not disconnecting agin (let's see for how long) So this gives us an idea that maybe the OS has some trouble at some point, or maybe the disk, but it's fixable in some way.

Someone with high level or understood in this area should be able to find a script to solve this without formating disk again.

I tested this with two WD and two Seagate, all APFS encrypted HHD.

I have 4 SSD different brands APFS encrypted and none had this problem never.

And in a different topic, but maybe related, since I upgraded to Ventura and SOnoma I had 2 disk of 6 plugged, failed something with the encryption, unable to connect them, one brand new, and the other 2 years old, this makes too many coincidences with Ventura and Sonoma for failed disks.

I think this issue is fixed for good in macOS Sequoia 15. Has been haunting me ever since I got the M1 MacBook Pro (never happened to Intel Macs), and this year's OS seems to have fixed the issue.

I'm using Seagate 5/4 TB drives & WD 1 / 2 TB SSDs. Tried multiple cables / devices and eventually confirmed it to be a macOS software issue specific to M series chips.

Bad news. I don't think this has been fixed. I have an M2 Pro MacBook Pro. For as long as I've had it, it has this "Disk Not Ejected Properly" issue. I now have my external drives connected via an OWC Thunderbolt dock, and haven't gotten those notifications for a while, but they just happened again. It continues to be a problem on macOS Sequoia, from 15.1 up through 15.5. Once or twice, these disconnects corrupted my encrypted Time Machine backups, causing me to lose ALL my backup history. I have my Mac set to: "Prevent automatic sleeping on power adapter when the display is off" "Put hard disks to sleep when possible: NEVER"

In the Terminal, I can run this: pmset -g | grep sleep And get this result: hibernatefile /var/vm/sleepimage networkoversleep 0 disksleep 0 sleep 0 (sleep prevented by nsurlsessiond, powerd, useractivityd, bluetoothd, mds_stores, backupd, sharingd) displaysleep 10

I've noticed this is a LOT more common when I haven't been at my Mac for over 24 hours. Looking at the logs, I found the following, which was during the time the Mac was locked, but supposedly not asleep: 2025-07-05 13:13:33.274200-0400 0x1593c5f Default 0x0 508 0 diskarbitrationd: [com.apple.DiskArbitration.diskarbitrationd:default] ejected disk, id = /dev/disk5, ongoing. 2025-07-05 13:13:33.274591-0400 0x1593c5f Default 0x0 508 0 diskarbitrationd: [com.apple.DiskArbitration.diskarbitrationd:default] ejected disk, id = /dev/disk5, success. 2025-07-05 13:13:33.643571-0400 0x1593c5f Default 0x0 508 0 diskarbitrationd: [com.apple.DiskArbitration.diskarbitrationd:default] ejected disk, id = /dev/disk4, ongoing. 2025-07-05 13:13:33.652292-0400 0x1593c5f Default 0x0 508 0 diskarbitrationd: [com.apple.DiskArbitration.diskarbitrationd:default] ejected disk, id = /dev/disk4, success.

So, it looks like, despite my settings, something in macOS has decided that a "long" period of user inactivity means it can do a (partial) sleep, disregarding user settings. I think that what is happening is that at some point it was decided by Apple that user settings should be disregarded when it comes to power management. Something that makes this even more frustrating is that whatever system process decides to eject the disks in disregard of our settings cannot even do it properly. So, we get system notifications chastising us for the improper disconnects, as if we were yanking out the cables or something. I'm going to have to use something like this command to make my Mac NOT eject disks on its own: caffeinate -i Or, I think I'll try the Amphetatmine.app, which puts a nice GUI interface, complete with triggers on this.