Chassis/Host power control and power state transition

[Andrew Geissler]

> On Dec 20, 2019, at 3:03 AM, rgrs <rgrs at protonmail.com> wrote:
> 
> Hi All,
> 
> Sometimes when I do "ipmitool chassis power cycle",  system gets powered off but not powered on back again.
> Logs show some sd_bus_set_property returns errno 5 (Input/Output error).
> 
> My guess is that CPLD that takes care of power distribution  in my server is causing the IO error, but i need enough data/logs to prove it.
> 
> I'm not able to debug further without understanding the state machine, system targets, and their order of execution.
> Is there any docs to tools to help me understand or visualize the execution sequence (for power operations atleast)?

https://github.com/openbmc/phosphor-state-manager/blob/master/README.md and
https://github.com/openbmc/docs/blob/master/architecture/openbmc-systemd.md are
good places to start.

Unfortunately we have not had a lot of luck with visualization. I have an issue,
https://github.com/ibm-openbmc/dev/issues/944, to look into doing something
with systemd-analyze but haven’t made much progress.

Usually when debugging failed systemd services, systemctl and journalctl
are going to be your debug tools.

Andrew

> 
> 
> Thanks,
> Raj
>