On a very large scale, greener computing practices can make a large difference in power usage, both in the home and the enterprise. With marginal up-front time and money investment, businesses can reduce their power usage (and bill) while at the same time using less power. Unfortunately, not all green initiatives are undertaken, and not all are truly beneficial.
Furthermore, CIOs are not always concerned with saving money on the utilities bills if the IT department is not billed for its usage. Some solutions to lower energy usage require a bit of re-engineering, and justifying the staff time is difficult unless it is made a priority. This is starting to change, but there are plenty of businesses still lagging behind, because the CFO has not gotten angry enough yet. Sustainability is, after all, efficient (especially in computing).
Desktop Computing: Thin Terminals, LCDs, Sleep
“But workstations need to be powered on all night so we can push out software updates.” Going back to the need to innovate to overcome simple hurdles, this is the perfect example. Wake-on-LAN can be used to wake computers for a few hours every night or once a week at night for patch installation. Tons of software is available for this, and even overall power management. Faronics, for example, offers Power Save, a program that can be installed on all workstations and monitored centrally. It even tells you how much power was saved, and calculates dollar amounts based on how much you pay for electricity. The savings, and the resulting lowered drain on the public power grid, can be surprisingly substantial.
Many studies have also been done on thin clients versus traditional workstations. It has been estimated that replacing an old CRT monitor and workstation combination with an LCD and thin client can bring power usage down to as little as 30W from 220W. Equally interesting is that this solution centralizes management and lowers IT support and software costs. Why run a separate OS instance on a spinning hard drive for each office worker, when all they are doing is e-mail and general office applications?
Server Virtualization
Does server virtualization really save power? On the surface, the answer is yes. If you can consolidate 50 physical servers onto 20 physical servers, you are running 30 fewer. This is all most people look at, but taking a deeper look at virtualization and the use-cases is in order.
The other promise of virtualization is better utilization of servers. Most of the 50 servers mentioned above likely didn’t come close to being fully utilized; in fact their own CPU power management features enabled power savings due to that underutilization. For example, an idle dual Xeon server may be drawing 150W of power. Start a CPU-intensive job, and it quickly uses 250W of power. So if we’ve reduced our physical server footprint by 30 servers, we have likely increased power usage by 3,000W. In terms of power usage, we’ve only saved 10 servers, or one-third of the amount we originally thought.
Another interesting thing happens when we virtualize as well. VM sprawl is certainly a problem, but it may not be all bad. In terms of power usage, it’s bad, but in terms of supportability, flexibility, and convenience, it’s good. Virtualization also lends itself to clustering and rapid deployment, providing more resilient services than ever before. This is good in terms of service availability and IT agility, but these types of advancements quickly undermine any greenness gained by virtualizing. We have saved 10 servers’ worth of power in the above example, but now that it’s easy to test with VMs and provide VM instances to customers, we often deploy 10 or more new servers and use more power before virtualization.
The Blade Server Fallacy
Conceptually it makes sense that consolidating the physical footprint of multiple servers would improve efficiencies. Fewer fans to cool the individual units, consolidated power supplies, and more, were all promised to save substantial amounts of power. It turns out that the savings is negligible, and sometimes non-existent. The media has been all over this recently, so we won’t dwell on it here; just beware of the blade server claims. They are useful, however, in consolidating management efforts.
Cloud Computing: Better Than Virtualization
The nature by which cloud computing is billed means that rampant VM provisioning will be limited. The large amount of servers running a cloud infrastructure can realize savings benefits when utilization is limited to what is actually necessary. In that way, it is a more effective savings to move your VMs into the cloud.
Utilizing software as a service, also considered a cloud-like model, means you don’t run servers yourself. This is becoming more popular as a means to reduce the IT burden, but in the grand scale of things, SaaS also allows providers to consolidate applications worldwide and realize the green benefits.
This type of wide scale consolidation is the most able and most likely to enable sustainability. That is, if companies turn off as many locally run services as they move to the cloud. Reducing power usage and IT burden can be done on many fronts, but it is more common to see outsourced applications complement rather than replace IT-run services. As SaaS and the cloud gains more traction, expect to see this wasteful trend decline, but it will decline even faster if we make conscience decisions. Decisions that, as it turns out, will also increase the bottom line at the same time.
When he’s not writing for Enterprise Networking Planet or riding his motorcycle, Charlie Schluting is the Associate Director of Computing Infrastructure at Portland State University. Charlie also operates OmniTraining.net, and recently finished Network Ninja, a must-read for every network engineer.
