I purchased a 4TB G-Drive USB 3.0 drive about a month ago and it has been working fine.
I just replaced my UPS with a new APC Back-UPS Pro 1500. It works fine. No errors or issues with the UPS.
Since I have connected the drive to to UPS I get “Disk Not Ejected Properly” notifications every 3-5 minutes.
This happens when I have the USB cable connected and disconnected from the APC unit to the iMac.
I have cycled through restarts and shutdowns.
Ran Disk First Aid on the drive 2 or 3 times.
Rechecked and plugged and unplugged all connections.
High Sierra V 10.13.5
4.2 GHz Intel Core I7
Retina 5K 27 2017
16 GB Memeory
Radeon PRo 580 8192 MB
3TB Fusion Drive
G Drive USC-C 4TB
I removed the drive from the UPS and connected dirctly to the outlet I have used before to take the UPS out of the equation.
Result - Still getting Disk Not Ejected Properly errors.
So I went back and did another First Aid on the drive.
It came back with the following Error report.
Repairing file system.
Volume was successfully unmounted.
Performing fsck_hfs -fy -x /dev/rdisk3s3
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Checking extended attributes file.
The volume G-Drive Time Machine could not be verified completely.
File system check exit code is 8.
Restoring the original state found as mounted.
Problem -69842 occurred while restoring the original mount state.
File system verify or repair failed.
The drive has gotten corrupted due to the improper disconnections.
First thing to check is your System Preferences > Energy Saver. Make sure the “put hard disks to sleep when possible” is unchecked. Also disable sleep mode on your computer entirely.
See if that still drops the connection. If it does then its possible there is a bad cable, or interface port on the drive. In that case we would recommend a replacement if under warranty. You can generate an RMA to get a replacement on our site at any time here: RMA creation