I guess you're referring to CPU Trigger led activity as defined by [0]?
As I said elsewhere, none of the (recent) servers I have access to, most of them Intel based, several distros, etc have anything else than LEDs defined for numlock/scrolllock under /sys/class/leds/, where I'd expect to find the CPU activity LED? What am I missing here?
There is a file in that directory for each physical led on your computer. You echo in the name of the "driver" for that LED (disk, cpu, heartbeat, whatever) and that physical LED becomes what the driver wants it to show.
So if numlock and scroll lock are the LEDs available on your hardware, you can repurpose one of those as the CPU activity LED.
As I said elsewhere, none of the (recent) servers I have access to, most of them Intel based, several distros, etc have anything else than LEDs defined for numlock/scrolllock under /sys/class/leds/, where I'd expect to find the CPU activity LED? What am I missing here?
[0]https://lwn.net/Articles/510986/