[systemd-devel] How to get hardware watchdog status when using systemd

[Zbigniew Jędrzejewski-Szmek]

On Tue, May 28, 2019 at 01:50:53PM +0200, Wiktor Kwapisiewicz wrote:
> Hi Zbyszek,
> 
> On 28.05.2019 13:43, Zbigniew Jędrzejewski-Szmek wrote:
> >What kind of information are you after?
> 
> One interesting statistic I'd like to see changing is the time when
> the watchdog was notified last.
> 
> For example, there is Timeleft in this wdctl output [0]:
> 
>   # wdctl
>   Identity:      iTCO_wdt [version 0]
>   Timeout:       30 seconds
>   Timeleft:       2 seconds

This currently isn't exported by systemd, and there's even no log
message at debug level. I guess this could be exposed, but I don't
think it'd be very useful. If the watchdog ping works, most people
don't need to look at it. If it doesn't, the machine should reboot...

If this is just for debugging, you can do something like

  sudo strace -e ioctl -p 1

and look for WDIOC_KEEPALIVE.

Zbyszek