Out of space on remote cloud

What is the state of the remote backup after getting a no space error from the cloud service?
Is there a partial backup stored?
or is the backup treated as atomic, either all there or nothing there?
Although I saw a popup notification, I don’t see any messages in to logs saying this happened.

If the remote sends an error back, Duplicati will notice and stop.
The backup is then consistent until the latest working backup.
Duplicati performs all operations such that deletion is done as the last step, keeping everything intact until then.