I recently switched to a G Drive (FireWire) as my TimeMachine backup drive. The initial backup worked ok, but after a few hours the backup failed saying it could not write to the G Drive. After rebooting, a few backups were successful but then the same message. I noticed that the G Drive powers down after a period of time, even though my Mac’s system setting say to never do that. I’m looking for suggestions on keeping the drive spun up and hoping that will solve the TimeMachine failure issue.
If your macOS Energy Saver System Preference has Enable Power Nap, you might try enabling (if not already set).
On a different note, although not with a G-Tech drive, I used a Firewire external drive, for Time Machine backups, for years and never had an issue with it spinning up just prior to a backup starting.
In an attempt to determine if something’s at issue with your drive, I’d try reformatting (using Disk Utility) to start over with a clean Time Machine backup and see if that resolves the issue. If not, I’d be thinking something’s maybe wrong with the hardware. …Just a thought.
