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!

@marcos@lemmy.world
link
fedilink
English
28M

Have you tried turning your swap off?

@PlutoniumAcid@lemmy.world
creator
link
fedilink
English
28M

Nope, haven’t. It says I have 2 GB of swap on a 16 GB RAM system, and that seems reasonable.

Why would you recommend turning swap off?

@marcos@lemmy.world
link
fedilink
English
38M

To check if your problem is caused by excessive memory usage requiring constant swapping. If it is, turning swap off will make some process be killed instead of slowing the computer down.

Max
link
fedilink
English
18M

The symptoms you describe are exactly what happens to my machine when it runs out of memory and then starts swapping really hard. This is easy to check by seeing if disk io also spikes when it happens, and if memory usage is high

Create a post

A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don’t control.

Rules:

  1. Be civil: we’re here to support and learn from one another. Insults won’t be tolerated. Flame wars are frowned upon.

  2. No spam posting.

  3. Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it’s not obvious why your post topic revolves around selfhosting, please include details to make it clear.

  4. Don’t duplicate the full text of your blog or github here. Just post the link for folks to click.

  5. Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).

  6. No trolling.

Resources:

Any issues on the community? Report it using the report flag.

Questions? DM the mods!

  • 1 user online
  • 94 users / day
  • 139 users / week
  • 268 users / month
  • 868 users / 6 months
  • 1 subscriber
  • 1.51K Posts
  • 8.6K Comments
  • Modlog