I'm storing all my photos (raws) in OneDrive. Enable a mechanism to sync keywords (or tags in OneDrive terminology) with Lightroom.
Since differential sync isn't supported on OneDrive I have to keep the database on DropBox.
As an amateur photographer with tens of thousands of photos in Lightroom, if OneDrive had more integration with Lightroom, I would be over the moon! Here's to hoping that the close relationship with Adobe can bring something like this about!