powernowd in server seed

James Dinkel jdinkel at gmail.com
Thu Sep 4 14:24:01 UTC 2008

On Thu, Sep 4, 2008 at 6:39 AM, Soren Hansen <soren at ubuntu.com> wrote:

> Hi, guys!
> I'm considering adding powernowd to the server seed, which means that it
> will be installed by default on server installs (unless you choose the
> minimal install method located in the "Modes" menu (press F4 to see it
> at the bootsplash)).  If the installed kernel supports the ondemand
> scaling governor, powernowd's init script simply tells the kernel to use
> that. If for some reason the kernel doesn't support this, it falls back
> to the userspace governor, spawns a daemon that monitors cpu usage and
> adjusts cpufreq accordingly. The win, of course, is that you'll save
> power, money, and the rain forest. :)
> Unless anyone objects, I'll file an FFe for this change, or at least
> queue it for Intrepid+1.
> --
> Soren Hansen               |

Will this automatically load the necessary driver modules, too?  On Hardy I
have to manually add 'acpi_cpufreq' and 'cpufreq_ondemand' to /etc/modules
in order to get the ondemand governor available.

Incidentally, I use the following lines added to /etc/rc.local for my home
server's power savings:
echo "   Enabling multi-core cpu power savings."
echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
echo "   Enabling on-demand cpu scheduling for cpu0."
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "   Enabling on-demand cpu scheduling for cpu1."
echo ondemand > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
echo "   Setting sleep timout for /dev/sda."
hdparm -S 12 /dev/sda
# add additional hard drives here
echo "   Putting kernel in laptop mode."
echo 5 > /proc/sys/vm/laptop_mode

Another option I've heard about to keep a company server more "green" is to
set a cron job to enable these features during off-peak usage hours and then
disable the power savings when you need faster response during peak hours.
There is also another option you can use with hdparm if your harddrive
supports power management features (mine doesn't).

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.ubuntu.com/archives/ubuntu-server/attachments/20080904/e5a26282/attachment.html>

More information about the ubuntu-server mailing list