[Beowulf] Green Cluster?

[Lombard, David N]

On Mon, Jul 21, 2008 at 10:58:56AM -0700, David Mathog wrote:
> 
> "Lombard, David N" <dnlombar at ichips.intel.com> wrote
> 
> > On Fri, Jul 18, 2008 at 10:20:54PM -0700, fkruggel at uci.edu wrote:
> > >
> > > Hi All,
> > >
> > > I am wondering whether there is any mechanism to automatically
> > > power down nodes (e.g., ACPI S3) when idle for some time, and
> > > automatically wake up when requested (e.g., by WOL, some cluster
> > > scheduler, ssh). I imagine that I could cut down power & cooling
> > > on our system by more than 50%. Any hints?
> >
> > The key is whether S3 is supported on your nodes; it's usually not
> > on servers.
> 
> The key is more often than not "how badly broken is the BIOS"?  We have
> two IBM X3455 systems with identical CPUs and the one with the older
> BIOS has CPU frequency control working, whereas the latest and greatest
> BIOS breaks it.  Here we're not talking about going all the way to S3,
> just providing the option to spin a bit more slowly when the system
> isn't busy.  Also, as somebody mentioned earlier in this thread, WOL
> which works but is not correctly initialized by the BIOS at power up is
> incredibly common (here is one: Asus A8N5X motherboard).

I meant "supported" in the larger sense, so, in order:
   Hardware
   BIOS
   OS (kernel & drivers)
   How you configure and manage it all in the userland...

with lots of fun interactions amongst them.  Once you can get the node
to go into, and *most* importantly, return from, S3, then you can work on
managing it via the resource manager.

> This is one instance where I wish the Federal government (and/or the
> European Union) would get off its collective duff and set a standard
...
> with this software when shipping a broken BIOS would result in fines.

As a Libertarian, I will respectfully disagree :)

-- 
David N. Lombard, Intel, Irvine, CA
I do not speak for Intel Corporation; all comments are strictly my own.