There is a new feature in Dropbox which allows you to back up the contents of an external hard drive, SSD, flash drive, etc. You may see a message when you connect an external drive, asking if you want to back it up.
This can be a nice way to back up a flash drive or external data drive, but Dropbox may ask if you want to backup your Carbon Copy Cloner and/or Time Machine external backup drive(s). Unless there is a compelling reason to make a redundant backup of your backup drive(s) to Dropbox, I recommend you click the “Don’t ask me again” box and click the “Not now” button:
If you do allow Dropbox to backup your external backup drive(s), note that those drives can contain a LOT of data and will possibly fill the capacity of your Dropbox account. In addition, the upload process will likely take a long time, making your internet connection perform more slowly during the upload. I don’t recommend this.
If you don’t want to see requests from Dropbox to backup external drives when you connect them in the future, you can disable this feature in Dropbox:
1. Click the Dropbox icon in your menu bar
2. Click the circular icon at the upper right.
3. Choose “Preferences…”
4. Click the “Backups” icon at the top
5. UN-check “Show setup notifications when new external drives are plugged in.”:
Now when a new external drive, flash drive, etc. is connected, Dropbox won’t pester you about backing it up.
If you’ve already allowed Dropbox to backup your external backup drive(s), you will see an icon in your Dropbox with the name(s) of the external drives. For example, note the “Kirk’s Flash Drive” icon in my Dropbox below. You can safely delete these items from your Dropbox account to save space: