Every couple of days I get this message that "iCloud Storage is Full" in a window on my MacBook, it is very annoying, as I know my storage is full and that I need to upgrade it. The window only gives me two options, "Manage" and "Upgrade", either of which opens up System Preferences, which wouldn't be such an issue if my internet connection was faster, but it takes System Preferences way too long to retrieve info about my iCloud Drive and I can't close System Preferences until it does. One cannot hide the window by clicking into another app.
How can I disable these iCloud Drive messages from appearing (perhaps from a Terminal command)? I am using OS X 10.11 "El Capitan", if it makes a difference.
I'm really looking for something that will just prevent this window from launching, maybe via a Terminal command or deleting/renaming a file, rather than just giving in and buying more storage or freeing some space.