I use Duplicatie for local backups (external drive). My files are synced with OneDrive as part of my Office365 account. Can I regard OneDrive as an online backup or should I backup to another target? E.g. if OneDrive fails, can my local files be wiped due to synchronisation?
If you mean can your Desktop, Documents, and Pictures be damaged by a OneDrive error, presumably, but you’re asking in the wrong place. They can also be damaged from another computer that is participating in same sync but has gotten malware one it, e.g. encrypting it.
Having another backup gives you more control of what and when, however it has limitations. What do the OneDrive icons mean? shows how files might not actually be on your computer.
This saves space on your computer, but can make it hard on backup programs to get the file.
Or have you already hit that and solved it well enough?
For an overview (etc.), you can try a Google search for: