This article offers guidance on how to avoid unexpected disconnection of external drives on a Mac.
When an external drive is disconnected from a computer without being safely ejected, a message stating "Disk Not Ejected Properly" typically appears. Nevertheless, some users have reported incidents where drives are unexpectedly ejected after updating their macOS. The majority of these reports suggest that the problem occurs after the computer has been in sleep mode. The following prompt exemplifies this issue:
Random ejection of an external drive can be caused by several factors, such as:
1. A faulty external drive cable2. A faulty external desktop drive power supply
3. A faulty USB or Thunderbolt port on the computer
4. A failing external drive
5. An issue related to the macOS update or the update process.
Troubleshooting steps:
1. Try using a different cable to connect the external drive.2. Test the external desktop drive with a different power supply.
3. Connect the drive to a different USB or Thunderbolt port on your computer.
4. Run First Aid to diagnose your external drive. You can find instructions here.
5. Reset the NVRAM or PRAM on your Mac.
Ways to Prevent Unexpected Ejections
1. Safely eject the external drive: Always use the "Eject" option or drag the drive to the trash can before disconnecting it to ensure a proper disconnection.2. Avoid sudden power loss: Make sure the external drive is connected to a stable power source and avoid abrupt power interruptions.
3. Check cable connections: Ensure that the cables connecting the external drive are securely plugged in and not loose.
4. Update macOS and drivers: Keep your macOS and device drivers up to date to ensure compatibility and minimize potential issues.
5. Avoid physical impacts: Handle the external drive with care and avoid subjecting it to physical shocks or impacts that could cause disconnections.
6. Disable sleep mode: Adjust your computer's sleep settings to prevent it from going into sleep mode while the external drive is in use.
7. Use a reliable drive enclosure: Invest in a high-quality drive enclosure that provides a secure and stable connection between the external drive and your computer.
Safely Ejecting When Not Using
The best method to avoid unexpected ejections is safely ejecting the drive when you are done using it. Use one of the methods listed below to eject an external drive:
1. On the desktop right-click the drive then choose Eject “Drive Name”2. On the desktop, drag the external drive to the Trash
3. In Finder, click the Eject button next to the external drive
How To Preventing computer and drive from sleep
If your external drive was functioning correctly before upgrading your macOS, and the ejection issue started after the upgrade, it could be related to macOS. In such a case, preventing both the computer and external drive from sleeping can prevent unexpected ejections. Follow the steps below:
Adjusting Energy Saver settings on a MacBook
- Click on the Apple icon then select System Preferences/System Settings
- Click on Energy Saver
- Click on Power Adaptor
- Enable “Prevent computer from sleeping automatically when display is off”
- NOTE: Prevent computer from sleeping when display is off may not be available for all versions of macOS
- Disable “Put hard disks to sleep when possible”
MacBook Pro Energy Saver
Changing Mac’s Energy Saver settings on iMac and Mac Mini
- Click on the Apple icon then select System Preferences/System Settings
- Click on Energy Saver
- Enable “Prevent computer from sleeping automatically when display is off”
- NOTE: Prevent computer from sleeping when display is off may not be available for all versions of macOS
- Disable “Put hard disks to sleep when possible”
iMac Energy Saver
Mac Mini Energy Saver
Note that even after changing these settings, your drive may still eject if you manually put your Mac to sleep. To prevent this, it's recommended to safely eject your drive before putting the Mac to sleep.
