PlutoniumAcid

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!

TLDR: VPN-newbie wants to learn how to set up and use VPN.

What I have:

Currently, many of my selfhosted services are publicly available via my domain name. I am aware that it is safer to keep things closed, and use VPN to access -- but I don't know how that works.

• domain name mapped via Cloudflare > static WAN IP > ISP modem > Ubiquity USG3 gateway > Linux server and Raspberry Pi.
• 80,443 fowarded to Nginx Proxy Manager; everything else closed.
• Linux server running Docker and several containers: NPM, Portainer, Paperless, Gitea, Mattermost, Immich, etc.
• Raspberry Pi running Pi-hole as DNS server for LAN clients.
• Synology NAS as network storage.

What I want:

• access services from WAN via Android phone.
• access services from WAN via laptop.
• maybe still keep some things public?
• noob-friendly solution: needs to be easy to "grok" and easy to maintain when services change.

I mean, the simplest answer is to lay a new cable, and that is definitely what I am going to do - that's not my question.

But this is a long run, and it would be neat if I could salvage some of that cable. How can I discover where the cable is damaged?

One stupid solution would be to halve the cable and crimp each end, and then test each new cable. Repeat iteratively. I would end up with a few broken cables and a bunch of tested cables, but they might be short.

How do the pro's do this? (Short of throwing the whole thing away!)