I run an old desktop mainboard as my homelab server. It runs Ubuntu smoothly at loads between 0.2 and 3 (whatever unit that is).
Problem:
Occasionally, the CPU load skyrockets above 400 (yes really), making the machine totally unresponsive. The only solution is the reset button.
Solution:
I haven’t found what the cause might be, but I think that a reboot every few days would prevent it from ever happening. That could be done easily with a crontab line.
alternatively, I would like to have some dead-simple script running in the background that simply looks at the CPU load and executes a reboot when the load climbs over a given threshold.
–> How could such a cpu-load-triggered reboot be implemented?
edit: I asked ChatGPT to help me create a script that is started by crontab every X minutes. The script has a kill-threshold that does a kill-9 on the top process, and a higher reboot-threshold that … reboots the machine. before doing either, or none of these, it will write a log line. I hope this will keep my system running, and I will review the log file to see how it fares. Or, it might inexplicable break my system. Fun!
Here’s a better suggestion. Why don’t you see if you can find out what’s causing the issue? It sounds a like a problem occurring in userspace. Try running htop
You know you are right, and I’ve tried. I can manually monitor but it doesn’t happen just then. I don’t know yet what causes it, I can only assume it’s one of the Docker containers because the machine is doing nothing else.
I am doing this to find out how often it happens, how quickly it happens, and what’s at the top when it happens.
I can manually monitor but it doesn’t happen just then
Setup proper monitoring with history. That way yo don’t have to babysit the server, you can just look at the charts after a crash. I usually go with netdata
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Here’s a better suggestion. Why don’t you see if you can find out what’s causing the issue? It sounds a like a problem occurring in userspace. Try running htop
You know you are right, and I’ve tried. I can manually monitor but it doesn’t happen just then. I don’t know yet what causes it, I can only assume it’s one of the Docker containers because the machine is doing nothing else.
I am doing this to find out how often it happens, how quickly it happens, and what’s at the top when it happens.
Maybe try capping the resource usage of each container. At least then the machine won’t completely lock up
That’s a good idea, didn’t know Docker had such capability. I will read up on that - could you give me some keywords to start on?
I very recently spun up a vps and wanted to limit resources; I use docker-compose so this was the info I needed https://docs.docker.com/compose/compose-file/compose-file-v3/#resources
Setup proper monitoring with history. That way yo don’t have to babysit the server, you can just look at the charts after a crash. I usually go with netdata