You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Time Machine

In trying to use a new external drive for Time Machine backup, I got a message that Time Machine needs to erase a Seagate drive in order to use it for backups. I clicked OK to erase, which was performed, but that got an error message "There was an error preparing the Time Machine backup disk “Backup 6. Couldn't unmount disk”. I manually erased the disk but I still get the error message, and am stuck at this place. Time Machine won't permit the new drive to be used for back up. Suggestions? Thank you!

MacBook Pro 15″, macOS 10.13

Posted on Sep 29, 2021 4:48 AM

Reply
Question marked as Top-ranking reply

Posted on Sep 29, 2021 6:58 AM

Erase the disk in Safe Mode. [hold shift at startup and be prepared with your userid and password.]


The device is likely controlled by the manufacturer's Driver, which is simulating a Mac Volume in a file.


If it refuses to erase in Safe Mode, ask again immediately, and often it will proceed.

2 replies
Question marked as Top-ranking reply

Sep 29, 2021 6:58 AM in response to aardvarknyc

Erase the disk in Safe Mode. [hold shift at startup and be prepared with your userid and password.]


The device is likely controlled by the manufacturer's Driver, which is simulating a Mac Volume in a file.


If it refuses to erase in Safe Mode, ask again immediately, and often it will proceed.

Time Machine

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.