The Least-Power Problem

Opinion: Effective management requires understanding of all system operations.

For enterprises to become greener, both in terms of a reduced environmental footprint and in dollars diverted from electric company coffers, they must grow as cognizant of power consumption as they are of security permissions—a principle of least power to accompany that of least privilege.

As with security design and implementation, going green isnt as easy as pulling a product off the rack and popping it into your infrastructure. Effective power management requires that administrators be able to monitor, understand and adjust the processes that compose their system operations.

For Linux-based operating systems, whose source code underbellies are laid bare across various mailing lists, project wikis, IRC (Internet Relay Chat) logs and source repositories on the Internet, theres no shortage of information required to illuminate and attack the least-power problem.

What the push for smarter Linux power management has lacked, however, is a good place to aggregate relevant information and coordinate efforts. Enter the Intel-sponsored, a project that the company announced at its recent developer forum in San Francisco.

The Less Watts project offers an impressive collection of Linux power management resources, including some good power-primer information, tips for cutting down on Linuxs power consumption and a handful of applications to download.

I took one of those applications, named PowerTop for its similarity to Linuxs terminal-based top process monitor, for a spin on my ThinkPad T60 notebook. PowerTop gave me information about the current state and recent past of my processors frequency scaling and listed the applications responsible for the majority of processor wake-ups.

The utility also offered suggestions for reducing power consumption, the terminal command Id need to enact those suggestions and the option to hit a key to enact the suggestions. For instance, PowerTop told me that I could save power by shutting off Bluetooth (which is built into my notebook but Im typically not using) or by disabling the wireless power-saving mode on my Wi-Fi adapter.

I couldnt enact all PowerTops suggestions so easily, and some of the tweaks might be best left to ones Linux distribution of choice. For instance, one tip called for a recompile of my kernel, and another would have enabled the power-saving features of my SATA hard drive but at the cost of disabling CD-ROM auto-detection.

While PowerTop and the rest of the resources at arent some green IT magic bullet, the window into power management on Linux that the project opens to users, administrators and developers is vital to the success of these efforts.


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