3 ms·

I was surprised at the poor state of watchdogs in PC-class Linux systems. I needed one recently and was bummed at the state of the old watchdog daemon / softdog

I was surprised at the poor state of watchdogs in PC-class Linux systems. I needed one recently and was bummed at the state of the old watchdog daemon / softdog kernel module. It works, but it is not nearly as easy to get going (on Ubuntu) as I expected. systemd also has its own watchdog and I can't figure it out. Anyway turns out I really needed a full PC hardware watchdog. I ended up buying some $8 anonymous piece of Chinese hardware that's USB powered. It hits the motherboard reset switch if the motherboard hard drive activity light hasn't flashed in awhile. Dumb thing, but it seems to work.

kjs3 7y ago
I found the same thing. Last time I needed a reliable PC watchdog it was an ISA (really PC/104) bus card that triggered a relay (causing reset) if a timer expired and a set of conditions hadn't been met.
agapon 7y ago
Almost all consumer motherboards have a chipset with embedded hardware watchdog that's well supported by respective drivers in FreeBSD / Linux / etc. Some vendors like Intel may lock down that functionality, but most (Asus, Gigabyte, etc) don't.
- NelsonMinar 7y ago
  Do you have any more info on that chipset watchdog and how I'd use it in Linux? Is it this, the TCO Watchdog? http://www.madore.org/~david/linux/iTCO-wdt-test.html http://www.madore.org/~david/linux/iTCO-wdt-test.html
  - agapon 7y ago
    Yes, iTCO_wdt is for Intel chipsets; sp5100_tco is for AMD chipsets (including FCH). The names are a bit weird to my taste. FreeBSD ones sound a little bit better (but maybe I am just more used to them): ichwd (ICH WD) and amdsbwd (AMD SouthBridge WD).
    - NelsonMinar 7y ago
      Thanks! I somehow spent several hours researching how to run watchdogs on Linux without finding this. Seems like exactly what I need. While I'm here, systemd's watchdog docs are also pretty good: http://0pointer.de/blog/projects/watchdog.html http://0pointer.de/blog/projects/watchdog.html

kjs3 7y ago

I found the same thing. Last time I needed a reliable PC watchdog it was an ISA (really PC/104) bus card that triggered a relay (causing reset) if a timer expired and a set of conditions hadn't been met.

agapon 7y ago

Almost all consumer motherboards have a chipset with embedded hardware watchdog that's well supported by respective drivers in FreeBSD / Linux / etc. Some vendors like Intel may lock down that functionality, but most (Asus, Gigabyte, etc) don't.

NelsonMinar 7y ago
Do you have any more info on that chipset watchdog and how I'd use it in Linux? Is it this, the TCO Watchdog? http://www.madore.org/~david/linux/iTCO-wdt-test.html http://www.madore.org/~david/linux/iTCO-wdt-test.html
- agapon 7y ago
  Yes, iTCO_wdt is for Intel chipsets; sp5100_tco is for AMD chipsets (including FCH). The names are a bit weird to my taste. FreeBSD ones sound a little bit better (but maybe I am just more used to them): ichwd (ICH WD) and amdsbwd (AMD SouthBridge WD).
  - NelsonMinar 7y ago
    Thanks! I somehow spent several hours researching how to run watchdogs on Linux without finding this. Seems like exactly what I need. While I'm here, systemd's watchdog docs are also pretty good: http://0pointer.de/blog/projects/watchdog.html http://0pointer.de/blog/projects/watchdog.html