I'm having some trouble with a Cent OS 7 box.
The problems just started last week and I have made no changes to the server.
The disk keeps filling up several times a day from 83% to 100%.
As soon as it is full, Nginx can't generate full webpages.
If I run "yum clean all" the disk goes back to 83% and everything runs fine again.
I'm not run daily yum updates, so I'm not sure why "yum clean all" fixes it.
Any ideas how I can troubleshoot and stop this?
You must have the yum-cron package which check daily (with /etc/cron.daily/0yum-daily.cron) for updates and download them by default.
In /etc/yum/yum-cron.conf you have by default :
download_updates = yes
apply_updates = no
You can configure yum-cron to apply them, or send you an email so you can apply them manually and clean instead of re-downloading each update daily after previous clean.
You can use tools such as http://diskreport.net to diagnose where you space usage grow between two dates