OneDrive deleted local and cloud files

I had an issue with the OneDrive (OD) app where it was bogging down File Explorer.  Simple navigation in File Explorer caused a long running busy cursor.

Since I needed to get work done, I RMB'd the cloud icon, Settings, Pause Sync, Quit OneDrive.  Whether that was right or not, I was simply following choices that were presented to me and I assume were allowed and harmless.  I did get a message that syncing would be stopped.  Fine, I'll turn on sync at the end of the day.

When I turned sync back on, EVERY ONE of the folders under the root OD had a red X.  OD's "solution" was to delete all these folders, and let OD re-sync from the cloud.  All 800GB. 

That's the best Microsoft can do when there is a metadata issue?  How about a file comparison between local and cloud folders, like rclone (free) or Beyond Compare ($50 for Pro Version) can do.  Then resync only those files necessary.

Anyway, I quickly turned sync back off and went home.  I'll deal with this in the morning.

Meanwhile, overnight there had been a Windows update and forced reboot of my machine.  (Note: there are Linux machines that haven't been rebooted in years.)  When I logged in I saw that OD had relaunched itself, and around half of my local OD files had been deleted.  I immediately checked the online recycle bin and saw that no online files had been deleted.  Whew, that's a relief.  Now if only Microsoft placed a value on my time.

By now I've lost all faith in OD, so I left it off, discovered rclone (https://rclone.org), and downloaded all my OD cloud files to external USB over the course of several days.

During this process, I discovered that my entire music collection had been deleted from the cloud.  These were legal files of CD's that I had purchased.  I never received any notification from Microsoft that they were deleting my cloud files.  The weird thing is the directory structure was still in place.  I could see the artist and album titles, only the .mp3 and .m4a files were missing.

My advice:  don't trust OD to properly safeguard your data.  Have a backup as well.  If you do use OD, for example due to the free 1TB storage that comes with an O365 subscription, disable/uninstall the OD app and use rclone to sync your files instead.  Use scheduled tasks to automate the process, and use sync logs to capture sync or copy results.  Send yourself an email or another alert if an operation ends in error.  Finally, with rclone + WinFsp, you can mount your OD cloud storage as a virtual drive (built in to Google Drive, although I don't use them either).  Much better than the "cloud only pointers" in the file system although yes, you would need to manually copy files from that mount point to your desired directory to work with them (with any acceptable speed).  Your next rclone sync job would copy it to the cloud.

If your online data is important to you I recommend you consider other cloud providers.  The low amount you'd pay would be worth it rather than important files go missing.  After deep research over a couple weeks I went with Mega.  So far so good and much superior to OD, both online and their sync app.  DYOR, YMMV.

I did open a support ticket for the missing music library but as expected received no help or sympathy from Microsoft.

But don't take my word for it.  Here is a chat transcript from ChatGPT about this issue:  https://chatgpt.com/share/68730707-3e14-8007-a0d7-ea3801c0dbe3

And to confirm ChatGPT's results I did the exact same prompting of Copilot (owned by Microsoft): https://copilot.microsoft.com/shares/1PvUsJBk3xDRUZcqx37VA 

I hope this information from my negative experience with OneDrive is useful.