Apologies for skirting close, but I think power consumption and heat dissipation are pretty big operator costs, and anything we can do to reduce those are beneficial to the bottom line; never mind the environment. More below:
-----Original Message----- From: Karl Southern [mailto:karl@theangryangel.co.uk] Sent: Thursday, May 14, 2009 1:10 AM To: Tomas L. Byrnes Cc: nanog@merit.edu Subject: Re: questions about DVFS in saving energy
Tomas L. Byrnes wrote:
Basically the CPU scaling on the host makes the guest OS fall apart.
Apologies for the general noise (and even more apologies for stepping outside of the nanog scope), but if it's timing related issues does /usepmtimer not resolve this issue for the VMs? It certainly does on other virtualisation solutions.
[TLB:] We tried all the solutions we could Google, including /usepmtimer. A potential 50% reduction in power per system (which is what we were measuring in the tests) would be significant. Unfortunately, it was not stable. It appears to be a Win2K3 issue, although Red Hat Enterprise ran at the declock speed all the time, even under heavy loads (it didn't crash and corrupt volumes like Win2K3, however).