How to prevent frequent disk ejection errors on iMac's external backup drive?

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Level 1

12 points

How to prevent frequent disk ejection errors on iMac's external backup drive?

My wife is getting annoyingly frequent disk ejection errors, see attached screen shot. The backup disk is permanently connected by a USB cable to her 24" iMac, M1, 2021, running in French, OS 15.6.1. Following a wake up, and during normal use, she gets a large number of these messages, that are only dismissible individually. The disk has not been ejected by her. Backups may have been done, but not explicitly by her, since automatic backup has been set up.

You will note that there are 2 volumes set up on the external drive. The drive is a Seagate 4Tb One Touch storage device that has cleared the disk utility SOS test.

How do we prevent this from happening?

[Edited by Moderator]

Original Title: Frequent Disk Ejection Errors

iMac (M1, 2021)

Posted on Dec 16, 2025 1:32 PM

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Answer 1

Dec 16, 2025 2:06 PM in response to Benzo42

Start by updating the iMac to 15.7.3

Then change the cable that connects the drive to the iMac. Use a quality cable rated for USB-3 and/or Thunderbolt 3. Use no adapters if possible.

There are any some apps or utilities that might cause problems. If there are anti-virus, cleaning security or VPN apps that have been installed on the Mac, it would be wise to uninstall these for the time being as you troubleshoot the problem.

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Answer 2

HWTech

Level 9

68,660 points

Dec 16, 2025 7:24 PM in response to Benzo42

Is the cable long enough so that the external drive can sit solidly on the table, but not long enough that the cable will be bumped or pulled or dislodged (even partially)? The USB port cable connection may not be able to withstand having the computer moved, or the cable moved/bumped.

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Answer 3

Old Toad

Level 10

215,346 points

Dec 16, 2025 2:42 PM in response to Benzo42

What type of drive is it: HDD or SSD?

If an HDD does it have its own power supply?

Which port is it plugged into?

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Answer 4

Yer_Man

Level 10

165,912 points

Dec 16, 2025 2:58 PM in response to Benzo42

As well as the other advice I would check the ports on the drive adn the Mac for lint and dust.

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Answer 5

Dec 17, 2025 2:25 AM in response to Benzo42

I had this problem when I plugged my external drives into unpowered USB hubs. Are you plugging directly into the iMac or via a hub? Since using powered hubs I no longer have the problem.

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