This setup will work for most cloud storage types (OneDrive, Google Drive, etc.) installed as an application on your Mac. In this guide, I will be using Google Drive.
1. Hit cmd+spacebar, which will open a spotlight search window and search for disk utility. You can also search by clicking on the magnifying glass in the upper right corner or search for it in the application folder.
2. While the disk utility window is active, create a new image from File > New Image > Blank Image. The file menu is to the right of the Apple icon.
3. Create a logical name for your specific device to make it easier to differentiate backups from different devices. E.g., If you have an iMac from 2017, name it iMacTM17.
4. Choose the location of your cloud storage. I recommend creating a dedicated “TimeMachine”-folder to keep it separate from everything else. As an extra layer of security, you can also create a “DO NOT DELETE”-folder
5. Name: same as step 3
6. Size: I recommend you create a disk double the size of your device. I have a 1TB drive and choose size 2 TB in this case.
7. Format: Mac OS Extended (Journaled)
8. You must encrypt your backup. Otherwise, anyone with access to your cloud storage would get a clone of your device. I don’t mean unintended access to cloud storage, but accidental sharing of the wrong folder. In this case, I use 256-bit AES encryption.
9. Create a strong password using a password manager, or create a passphrase. You must remember this. Without it, the backup is useless.
10. Partitions: Single partition - Apple Partition Map
11. Image format: Sparse bundle disk image
12. Doublecheck your size from step 6. Sometimes it resets.
14. You can now see the newly created disk image in the left panel in the Disk utility.
If you try to open Time Machine and select your newly created disk image, it won’t be visible. We need to do an additional step for the disk to be visible and compatible with Time Machine.
The following steps required administrator privileges, and that terminal has full disk access. Give terminal full disk access by opening system preferences > security & privacy > privacy > scroll down to full disk access > make sure Terminal checkbox is checked. Make sure to unlock the padlock in the lower-left corner before hitting the checkbox.
As mentioned, you will need to open a terminal window. Do not be scared. Just follow my commands :)
1. Open Terminal windows by searching for “terminal” in spotlight search (cmd+spacebar) or the application folder.
2. Use this command exactly as written here: sudo tmutil setdestination /Volumes/<your disk image name>. Make sure there is space between setdestination and /Volumes. Check disk image name from step 3 in previous section. In my case, that would be McMiniTMBP20.
3. Hit Enter
4. Enter your local admin user password
5. Close Terminal
6. Open system preferences > Time Machine
7. The disk image is automatically selected
8. Check the “Back Up Automatically” box, and it will start automatically
9. If you want a manual start, check the “Show Time Machine in menu bar” box
10. In the upper right corner of your Mac, click on the Time Machine icon, and choose “Back Up Now”