Okay, so lately I've been getting a lot of 500 Internal Servers due to my /tmp folder filling up and preventing uploads. However, when I look inside it, the culprit is always a huge file called "magick-XXXUSKnT" or similar, which I believe is coming from ImageMagick.
However, the file is often huge, far larger even than any images my site handles, so it's clearly growing in size due to some kind of error, filling up /tmp then failing such that ImageMagick closes without discarding it. Even stranger is that ls often measures their size as several hundred megabytes, even though my /tmp folder has a limit of 128mb (I'm on a VPS).
Does anyone know what might be causing this? I've activated a more aggressive /tmp cleaning cron job to run every 15 minutes, to hopefully clear these files more quickly, but I really should figure out why they're appearing in the first place.