9GB Whew!
Are your settings very high?
max image size kb
The maximum image upload size in kB. This must be configured in nginx (client_max_body_size) / apache or proxy as well.
max attachment size kb
The maximum attachment files upload size in kB. This must be configured in nginx (client_max_body_size) / apache or proxy as well.
Or is this a member doing a mess of smaller uploads?