I think there is a message now, but it could be improved.
I received this personal message today, after upgrading the forum:
Downloading remote images disabled
The
download_remote_images_to_localsetting was disabled because the disk space limit atdownload_remote_images_thresholdwas reached.
The solution for me was:
cd /var/discourse
./launcher cleanup
(Total reclaimed space: 23.09GB)
I wonder whether the message could explain something about the problem and potential solutions.