I mentioned previously that I built out some new hardware. When I was spec’ing out the hardware, I made sure to get “green” components that supported advanced power management features. Solaris is able to take advantage of the CPU power states, and can lower the processor operating frequency when a server is idle. Power managementis handled by the the Solaris kernel, and configured through the /etc/power.conf configuration file. By default, the file will contain a CPU power management entry similar to the following:
cpupm enable cpu-threshold 1s
The cpupm directive enables CPU power management, and the cpu-threshold directive indicates how often the processor needs to be idle before the CPU frequency is lowered. To check the current operating frequency of a CPU, you can check the current_clock_Hz value for each CPU:
$ kstat -m cpu_info -i 0 -s current_clock_Hz
module: cpu_info instance: 0
name: cpu_info0 class: misc
current_clock_Hz 1100000000
This is awesome stuff, and when the disk power management project is integrated, servers will hopefully be able to reduce their power consumption dramatically. Viva la Solaris!