Once the folder on an external disk is added to the Backup and Sync app, it syncs just like a folder inside the main Google Drive folder would. How does an external disk sync with Google Drive? I still have my main Google Drive folder synced to the built-in disk.

Note: I am using the external disk as an extension to my main Google Drive folder. I added the folder to the Google Backup and Sync app.I created a folder on an external disk and placed some files in the folder.I have a clean external hard disk connected to my Mac running the latest MacOS High Sierra.It mostly behaves as expected but I did find one weird bug. So I ran a few tests to verify the behavior. Unfortunately, there isn't good documentation on how exactly syncing an external drive behaves and answers on Google Product Forums aren't always complete and comprehensive. I wanted to be 100% sure how exactly it will play out because I'm not taking chances with my photos and videos. The folder can be on an external drive too but the challenge is that I normally don't keep the disk connected at all times. Google Drive allows you to sync a folder outside the main Google Drive folder. As much I trust Google, I still want to keep a local copy of all of my files and I want it to seamlessly sync with the cloud. I now have more data in Google Drive than can fit into my Mac's 500 GB of built-in storage. It's not well documented, so I run a few tests to understand how exactly Google Drive works with external disks. How Google Drive works with external disks

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