External Drives Keep Disconnecting on Sleep – Potential Data Loss Concern POSSIBLE SOLUTION

I have been having this problem for years. I had it with an Intel Mac working with a Caldigit TS3+ dock. And it is anything worse with my new M3 MBP Pro. So I have just found something which so far seems to solve the problem!!


It is a small extension called Ejectify which cost me €4.99. It tracks your mounted hard disks and unmounts them before sleep and then remounts them just after waking. Had it for 2 days. Seems to have solved the problem.


Amazing. NB I have nothing to do with them BUT should not Apple should buy their tech and add it to the OS and make the guy rich?

MacBook Pro 14″

Posted on Sep 15, 2025 07:49 AM

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Question marked as Top-ranking reply

Posted on Sep 15, 2025 08:16 AM

Although that is an interesting work-around for you, Apple is NOT 'fixing' this because it is Not Broken!


Disk not ejected properly:

This can be caused by a shortcoming of your external Bus Powered drive, and not of your Macintosh computer.


When you Mount any ejectable drive, the Directory from the drive is copied into RAM, and the directory on the drive is marked status = checked out (like a library book that has been borrowed from the lending library). The RAM copy is considered the Master copy, and changes that you make while working are made in the RAM copy of the Directory.


When you Eject/UnMount a drive, the RAM copy of the Directory replaces the copy on the drive, and the status of the directory on the drive is marked status = checked IN and Good.


Some external drives get all their power from the USB Bus. Bus-powered external drives should gracefully transition into standby and accept reduced USB power supplied when your Mac sleeps.


Some drives do this perfectly. Other drives do not transition gracefully and do not run only on standby power. Instead of stand-by, these drives disconnect. The problem is, the Directory from the drive has been checked out, and the Master copy in RAM has no way to get back to the disconnected drive.


Some Time later, when your Mac wakes up again, the drive reports 'I just woke up and am ready to connect'. Your Mac is confused because the drive will not CONTINUE from where it left off, so the Mac says "drive disconnected". The copy of the Directory on the Drive is Stale/checked out (not the Master copy). You get the messages "drive not ejected properly" the same as if you had pulled the cables out while running. The correct state of the Directory can not be determined instantly, but requires Disk Utility 'Repair Disk' procedure.


Summary: this is likely a deficit of the DRIVE, not the Mac. If any one of:

• the drive had external power -OR-

• the drive transitioned gracefully to standby -OR-

• the Mac did not sleep, THEN...

...this would likely not occur.


To resolve, you may need to launch Disk Utility and RepairDisk/FirstAid on the troubled drive.


a similar situation can also occur when a major error occurs on the drive. In that case, the drive is usually made Read-only, until you take steps to Repair it in Disk Utility.


1 reply
Question marked as Top-ranking reply

Sep 15, 2025 08:16 AM in response to tommybanana

Although that is an interesting work-around for you, Apple is NOT 'fixing' this because it is Not Broken!


Disk not ejected properly:

This can be caused by a shortcoming of your external Bus Powered drive, and not of your Macintosh computer.


When you Mount any ejectable drive, the Directory from the drive is copied into RAM, and the directory on the drive is marked status = checked out (like a library book that has been borrowed from the lending library). The RAM copy is considered the Master copy, and changes that you make while working are made in the RAM copy of the Directory.


When you Eject/UnMount a drive, the RAM copy of the Directory replaces the copy on the drive, and the status of the directory on the drive is marked status = checked IN and Good.


Some external drives get all their power from the USB Bus. Bus-powered external drives should gracefully transition into standby and accept reduced USB power supplied when your Mac sleeps.


Some drives do this perfectly. Other drives do not transition gracefully and do not run only on standby power. Instead of stand-by, these drives disconnect. The problem is, the Directory from the drive has been checked out, and the Master copy in RAM has no way to get back to the disconnected drive.


Some Time later, when your Mac wakes up again, the drive reports 'I just woke up and am ready to connect'. Your Mac is confused because the drive will not CONTINUE from where it left off, so the Mac says "drive disconnected". The copy of the Directory on the Drive is Stale/checked out (not the Master copy). You get the messages "drive not ejected properly" the same as if you had pulled the cables out while running. The correct state of the Directory can not be determined instantly, but requires Disk Utility 'Repair Disk' procedure.


Summary: this is likely a deficit of the DRIVE, not the Mac. If any one of:

• the drive had external power -OR-

• the drive transitioned gracefully to standby -OR-

• the Mac did not sleep, THEN...

...this would likely not occur.


To resolve, you may need to launch Disk Utility and RepairDisk/FirstAid on the troubled drive.


a similar situation can also occur when a major error occurs on the drive. In that case, the drive is usually made Read-only, until you take steps to Repair it in Disk Utility.


External Drives Keep Disconnecting on Sleep – Potential Data Loss Concern POSSIBLE SOLUTION

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