At some point recently, my fan stopped working. I've confirmed it's not the hardware, because in the bios I can start and stop the fan. This is an ubuntu 17.10 desktop host.
I noticed that lm-sensors
wasn't noticing the fan. With a bit of searching, I found that adding the it87 module to /etc/modules caused lm-sensors
to display temperature. (I'm not convinced I believe it for every probe it shows -- a few are negative -- but many of them look reasonable and move up and down with system load.)
As system load increases, I start seeing a bunch of processes like kidle_inject/0
, which I understand are related to the kernel trying to slow down the CPU to avoid overheating (injecting idle cycles). And, indeed, with increased load I used to hear the fan come on. But no longer.
Any suggestions on what to look at?