`<div dir="ltr">CPU power management is unlikely to do much for you. Its better to rely on C-states to save power on modern systems. That said, there are some known bugs with deep C states and some drivers; we don't ordinarily recommend setting it for servers.<div>
<br></div><div>The autopm should probably just be set to disable for your configuration. Letting the system power down your hard drives is likely to be the root of your problems. You don't need or want to power the drives down, and probably you don't want to power management anything else. (Frankly, very very few components on typical illumos based systems even support power management apart from the disk subsystem. The display subsystem typically uses its own power management which doesn't participate with the rest of illumos' power management framework, IIRC.)</div>
<div><br></div><div>Indeed, the illumos power management framework is kind of a shambles right now -- consisting of at least two separate generations of code, a high level of complexity, and almost no substantial support from the various things that *should* support it. </div>
<div><br></div><div>At one point I was discussing with Randy Fishel about some ideas I had for simplifying things substantially. Most generally, these days involvement with a core power management is probably *not* what you want, except to indicate "policy" -- modern devices (disk drives notwithstanding) can generally raise and lower power so quickly that its best to just let the drivers do their own power management explicitly, with only a few monitoring and policy hooks. This would lead to a vastly simpler power framework, which would probably be more likely to be taken up driver authors than the current mess.</div>
<div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Nov 12, 2013 at 2:52 PM, Paul B. Henson <span dir="ltr"><<a href="mailto:henson@acm.org" target="_blank">henson@acm.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I think the storage server I'm working on at home (current omnios stable) is<br>
spinning down disks; whenever I get back to it after not touching it for a<br>
while, anything touching my export pool (dual 6 x 3TB WD Red RAIDZ2) takes a<br>
long time to respond, and then goes back to normal.<br>
<br>
My current power.conf is:<br>
<br>
-----<br>
autopm enable<br>
autoS3 disable<br>
<br>
cpupm enable<br>
cpu_deep_idle enable<br>
cpu-threshold 1s<br>
-----<br>
<br>
I had thought that when running on server class hardware the default was not<br>
to spin down drives, but perhaps I was mistaken? Hmm, or maybe the default<br>
is to just skip power management completely, and explicitly turning it on<br>
turned on everything.<br>
<br>
I'm thinking about adding "system-threshold always-on" to the configuration,<br>
which I guess will disable all power down functionality, other than CPU,<br>
which is controlled by the "cpu-threshold" parameter? What other power<br>
savings would this turnoff? I am in general in favor of saving energy :),<br>
other than for the disks, as the latency is too high and causes too much of<br>
a delay, and it's not clear if setting the system-threshold to stop spinning<br>
down disks will also disable other potentially desirable power savings. I<br>
guess the other option would be to explicitly configure device-thresholds<br>
for all of the disks individually. Is there any way to list what components<br>
of a system support power management?<br>
<br>
While on the subject, any thoughts on event-mode vs poll-mode for cpupm?<br>
It's not clear from the man page what the default is if you just set it to<br>
"enable".<br>
<br>
Thanks.<br>
<br>
<br>
<br>
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