So, I upgraded some software on the server last night for a "minor security fix" Of course, the slightly newer version completely changed the layout of all config files. I complained about this in another thread already, but bottom line is I had to rewrite most of the webserver config from scratch. I think I got it all working, but I could've missed a bit of stuff here and there.
Then I wake up this morning, and all sorts of weird errors are cropping up. Took me 30 minutes to figure out what was even going on. It looked like permission problems or some such. But no, all that was fine. Turns out the root partition was full, as this month's traffic has been quite high, and the log file is well over 2 gigabytes in size.
Before you ask, no, deleting stuff you don't need won't help. The home/user directories are on a seperate partition. What helped, was that I had to go delete a whole lot of junk left from software builds, old logs, and various other cruft. We should be good now, and I apologize for the trouble.