[OmniOS-discuss] [discuss] illumos power management

[Paul B. Henson]

> From: randyf at sibernet.com [mailto:randyf at sibernet.com]
> Sent: Wednesday, November 13, 2013 10:44 PM
>
> CPUPM can be independent of autopm, so if you desire CPUPM and not disk
> PM, setting autopm to 'disable' is correct (note, autoS3 is only relevant

Well, my new draft is:

autopm                  disable
S3-support              disable
cpupm                   enable event-mode
cpu_deep_idle           enable

Which I think is doing what I want. Unless there is some other component
that would be willing to go into power savings mode other than the disks.

> Also, you *can* specify different PM capabilities for different disks.
> Multi-terabyte drives are cheap, and could serve as the backup media.
> There could well be value of having backup disks spindown, but keep the OS
> disks always-on (you would have to enable autopm for this action, though).

For this box, the only disks are either the production OS or the production
storage, but I could see that being useful for some type of online backup
box that is only accessed non-interactively once a day or so.

> Lastly, powertop(1m) can be used to see how well CPUPM is working for
> you.

Oooh, cool, I did not realize illumos included powertop. Looks like with the
above config on an idle box the majority of CPU time is in C3 and the
P-state is exclusively the lowest frequency. I'll have to run that again
once I get some load going.


>  It may be more than you might think.  The backlight on flat panels is
> the biggest draw, and may not be trivial.  A monitor rendering black will

Oh, it doesn't actually have a monitor attached. The box physically has a
VGA port, but the only way I've ever looked at the actual "graphics console"
is via the remote KVM app, which I only used when I was initially building
it. Serial consoles are much nicer for servers :), the only annoying lack is
that there is no way in the supermicro bios to select an alternate boot
device via the serial console. You can get into setup, but they haven't
mapped anything to pull up the boot menu :(.

Thanks much.