On: Windows NTFS Tricks Collection

[voltagex_]

Seems like it's done via a filesystem filter driver - calls to open files from OneDrive-unaware applications block until the file is downloaded.

[dataflow → voltagex_]

That's a different problem though, right? I thought you were asking where OneDrive stores the information necessary to know where the file is located on your cloud storage, and it would make sense for that to be in a stream.

[voltagex_ → dataflow]

Yep, but it looks like most things are done server side, then everything OS-side is done through the OneDrive client and a driver. AFAIK, this is the second implementation of "online files". Sorry, I'll stop dragging this offtopic now.

[sebazzz → dataflow]

Yes, but the stream will remain if copied to another NTFS volume. That may cause issues.

[dataflow → sebazzz]

What kinds of issues?

[sebazzz → dataflow]

If you copy indirectly from OneDrive folder to another OneDrive folder, the file may not sync due to the ADS indicating that the data is already uploaded.