G-Drive stopped backing up via Time Machine-Should I reformat?

My 2TB G-Drive has been backing up my MacBook Pro using Time Machine with no trouble since I purchased it last July of 2015.

However last week the Time Machine backup failed, and activity monitor shows fsck_hfs continually operating on the drive. Disk Utility recognizes the drive, and the verify disk function advises that I repair it.
Disk repair gives me:

Disk Utility stopped repairing “G-DRIVE”

Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files.

This happened last Thursday, but when I turned off the G-Drive and plugged it back in the following evening, the disk mounted and functioned normally again for a few days. However now it is exhibiting the same behavior as last week.

Do I need to reformat the disk? Is there anything else I can try before I do that? (I hate to lose a year’s worth of incremental backups.)

And what might have caused the disk to perform this way?

Thank you for your help!

My set up:
MacBook Pro (Mid 2009) Yosemite 10.10.5
Internal 250 GB SATA Disk
G-Drive connected via FireWire 800


The issue you are getting is that of a corrupted drive, small amounts at first and it can get worse. The best way to clean the corruption is indeed to format the drive. This will get rid of all the corruption and start it over.

There is another method for cleaning the corruption but it uses a 3rd party software to repair the drive. This software is called Disk Warrior and we recommend it to Mac users.

Unfortunately corruption on a drive like this is hard to pinpoint how it starts. It can be a few things. Disconnecting the drive without ejecting it first is one way, another is corrupted data in the backups themselves.

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Thank you so much for the quick reply!

I purchased the Disk Warrior software and was able to rebuild the directories so that the disk is no longer corrupted. In fact, according to the Disk Warrior readout, my disk is now 100% optimized–good as new. I am so glad I checked in here before reformatting it and losing Time Machine backups.

I really appreciate the comprehensive answer. It helped me a lot.


Sorry to hijack your thread but to understand, when you used the Disk Warrior software did it rebuild the directories without affecting the backups/data that were already on your G-Drive?
Or did you back them up elsewhere first?
Having the same/similar problem with my G-Drive but paranoid about doing anything to it as many similar forums mention backing up the backup first as reformatting/rebuilding the disk will wipe all the data. I have many things I don’t want to lose!
Thank you.

Hi Julie_Gray,
I’m happy to help.

I was able to recover all my Time Machine data with the Disk Warrior software. I did not back it up first because I’m not sure if that is even possible (because the files are indexed by date), plus I have a second back up off site on Carbonite. As my G-Drive is a copy of the data I already have on my computer, I felt it was sufficient to proceed with just the one backup on Carbonite until I had Time Machine back on line.
Reformatting would certainly wipe out all the data, but with Disk Warrior reformatting was not necessary. And my hard drive, as of today, is still performing perfectly.

Thank you Kirsten_B!

I don’t have any secondary backup :frowning:
Time Machine backs up my laptop - but I also have lots of photos that I’ve started storing only on my G-Drive and have deleted from my laptop as it is constantly running out of space, so I am very concerned at the possibility of losing these.
I can still access my G-Drive files (for now, at least) but can no longer use it for Time Machine (which I also need to!).
Sounds like Disk Warrior could very much be the solution to my problem (although my G-Drive is around 5 years old now, unlike yours) but it still makes me very nervous that I don’t have a further backup. I think I will try to sort a secondary backup before doing anything!