SFTP upload of files suddenly fails

Question

I am struggling to upload files via SFTP to my website server using several different ways.

The file upload script I had coded for a webpage (a simple form to php upload script) returns a "Invalid File" error; if I try to upload directly through Dreamweaver (which connects to the remote server successfully), I get a "Put operation failed" and with FileZilla I get an "Error while writing: failure" error.

Both systems worked as late as last thursday and no changes were made to the code, so I am at a loss to explain what could have caused the issue.

I read some users suggesting it may be an issue of space on the remote server, but I have deleted files bigger than the image I am uploading (which is 5kb) and the error still occurs so I would be inclined to exclude this option.

Thank you for your help!

Answer 1

As you mentioned, a full filesystem or exceeding disk quota is a common cause of the SFTP "failure" error with OpenSSH server (assuming you connect to that one).
See https://winscp.net/eng/docs/sftp_codes#code_4

While I understand you have tried to delete some files already, it does not mean this cannot be the cause of the problem. An admin might have decreased your quota below capacity you had occupied before. Check your quota explicitly.

Some SFTP clients allow this.

For example, WinSCP has this feature. See its Server and Protocol Information Dialog .
(I'm the author of WinSCP)

FileZilla does not allow this.