I am getting tons of (about a hundred) “Disk Not Ejected Properly” notifications/messages for two external hard drives (one drive has one partition, the other has two partitions). I'm running Mojave 10.14.4. I never had these issues when these two drives were connected to a MacBook also running 10.14.4. But, now I have them connected to an iMac and these messages have been displaying recently the past day. Had not happened for about a week's worth of use prior to yesterday. The disks still seem to be working fine but for some reason it's worrisome to me.


Both drives are connected via Thunderbolt 3. Under the "Energy Saver" preference pane, I have "Put hard disks to sleep when possible" and "Enable Power Nap" checked.

Also: Similar Issue and Similar Issue

  • 1
    To troubleshoot, try unchecking the Put hard disk to sleep option. If you don't need any of the activities PowerNap does while the Mac sleeps, then turn that off too. Also - are the drives daisy-chained or connected to their own ports? – IconDaemon May 8 '19 at 1:14
  • 1
    Those come and go in my experience. Power nap seems to sometimes not have enough juice for spinning HDD. I only see it in sleep, can you disable that to make sure it’s sleep/wake? – bmike May 8 '19 at 1:15
  • @IconDaemon I will try unchecking both of those. No the drives are not daisy-chained, both are connected independently – cryptic May 8 '19 at 1:18
  • @bmike Sure thing, I'll test that out. I have had this issue maybe once or twice that I can recall dating back to OS X 10.8 or so. Does this occur somewhat often for you just on Mojave or past OS versions also? – cryptic May 8 '19 at 1:21
  • I should also add that the external disks are of the spinning flavor (yuck) – cryptic May 8 '19 at 1:22

I started killing processes with "Notification" in their name, and when I hit the one called "NotificationCenter" the smoke finally cleared:

killall NotificationCenter
  • 1
    This is awesome to get rid of the bulk messages. We still have the underlying issue that the machine tried and failed to unmount the drive dozens of times over and over, but this is so much better than playing "whack-a-mole" with each notification that must be addressed with individual clicks. – bmike May 8 '19 at 12:10
  • Great tip to get rid of all the notifications, thanks! – cryptic May 9 '19 at 19:35

I was able to reproduce this exact issue the first time I tried last night. I don't have an answer, but I want to share how I'm set up and report some data in case it helps us troubleshoot this or determine how to narrow / catch / prevent this.

  1. I use LG displays (some 4K USB-C and some 5K Thunderbolt 3)
  2. I use MacBook (one) 2015 USB and newer and MacBook Pro USB C - some with Touch Bar and some without.
  3. The TouchBar models seem to me much more prone to both Machine Check / reboots and this issue, but all of the above Macs do enter this state from time to time and everything works before and after and we can't usually make it happen, so it's a timing or rare occurrence / not a "it always happens" sort of thing.

My "reproduce case" this morning was 13" TouchBar and I ejected the USB drive before putting the Mac to sleep by menu command. The USB drive was connected directly to the side of the Mac as was the USB-C 4k Display and integrated hub.

  • 1
    I tried out the suggestion you had and there were no issues yesterday. Today I reverted to having "Put hard disks to sleep when possible" and "Enable Power Nap" checked, and no problems so far – cryptic May 9 '19 at 19:42

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .