Bug? No information that storage has been exhausted

I am sure that I found a bug or unhandled case - during the backup creation process by SFTP Duplicati fills up the whole disk but there is no notification or error, just nothing. Duplicati is trying to upload the next file constantly, but can’t and is irresponsive - won’t stop if you use “stop” option. At the same time, Duplicati is showing that the upload file process is still pending with ~3KB/s.

Is it a bug or missing feature? (error handling or notification about problem)

Welcome to the forum @Iraetyrr_Waerrae

Usually an upload failure gets an error, and errors are retried based on –number-of-retries.
There should be a file renaming for each retry but the contents of the file remain the same.

About --> Show log --> Live --> Retry will let you view the action. Errors can be clicked on.
Setting up a disk –log-file at –log-file-log-level=retry is nicer, but a little more work to set up.

Basically, first question is whether SFTP server is reporting the error. If not, nobody knows.

SFTP does not appear able to report quota, though some versions report exceeded errors.
Duplicati has a rather generic view of storage and errors, though flavors exist (see below).

–quota-size can be set manually. This could give you a warning before quota is exhausted:

This value can be used to set a known upper limit on the amount of space a backend has. If the backend reports the size itself, this value is ignored.

Although the manual doesn’t document which storage providers will report quota size, code:

not saying IQuotaEnabledBackend says that it lacks that, therefore your manual setting should be taken.

Thanks for your response. As I understand it’s impossible to fix it, because it depends on provider (SFTP server implementation). Well, nothing to do.