Re:Debugging Hetzner: Uncovering failures with powerstat, se...
by nickcw on Wednesday February 19, 2025 @09:47AM
(#43102677)
Power = volts * amps
Volts is as supplied by the utility company.
Amps are monitored per rack and the usual data centre response to going over an amp limit is that a fuse blows or the data centre asks you for more money!
The only way you can decrease power used by a server is by throttling the CPUs.
The normal way of throttling CPUs is via the OS which requires cooperation.
I speculate this is possible via the lights out base band controller (which doesn't need the os to be involved), but I'm pretty sure you'd see that in /sys if it was.
Volts is as supplied by the utility company.
Amps are monitored per rack and the usual data centre response to going over an amp limit is that a fuse blows or the data centre asks you for more money!
The only way you can decrease power used by a server is by throttling the CPUs.
The normal way of throttling CPUs is via the OS which requires cooperation.
I speculate this is possible via the lights out base band controller (which doesn't need the os to be involved), but I'm pretty sure you'd see that in /sys if it was.