|
Today, most of the personnel own portable computing equipment, such as "notebooks" or "netbooks", and their Achilles heel is the energy management, since allowing the equipment to consume more than necessary, shortens the autonomy of the batteries. |
In graphical environments, there are almost no operating systems, and even more so under GNU / Linux, that do not have a graphical daemon that allows managing the different options that can be presented with a mouse click, such as suspend, hibernate or go to low mode. consumption.
But it is rare that one needs to do it from the console.
Why does this come to mind? Well, I recently received a netbook as a "remnant" whose owner no longer used it because its operating system had become too heavy, making the machine almost unusable. He mentioned something about XP and a number 7, but those are things I didn't understand. 
Well, the gadget is currently running a Debian 7 "wheezy" with an OpenBox screen manager, configured to the minimum expression, but this minimal expression made me investigate how to use the benefits of advanced power management from the console, since in In order to minimize resource consumption, I avoided installing anything that could be done from the console.
And there I came across pm-utils.
pm-utils
pm-utils, as stated on its page http://pm-utils.freedesktop.org, "is a small collection of commands that allow HAL to suspend and resume."
Just in case,
H (High): maximum utilization of the cooling system.
A (Auto): automatic temperature regulation system.
L (Low): minimum use of the cooling system. When it exceeds a certain limit, it goes into automatic mode.
The package installs automatically with any Debian base system, and has the following commands:
/usr/bin/pm-is-supported : is used to determine which power saving modes are supported by the system.
/usr/sbin/pm-powersave : toggles power saving mode, setting it to "L"
/usr/sbin/pm-suspend : suspends memory operations and puts the system at the lowest possible power consumption.
/usr/sbin/pm-hibernate : Hibernates the system by downloading all data from memory to the hard drive.
`/usr/sbin/pm-suspend-hybrid` : This puts the system into a state similar to hibernation, but in memory. That is, its recovery is similar to suspension, faster than normal hibernation, but if the battery runs out, it remains in a hibernation state without data loss, as would happen with a normal suspend. It's the best of both worlds, and my favorite.
The utility package has excellent documentation in English, and configuration directories /etc/pm/config.d, /etc/pm/sleep.d and /usr/lib/pm-utils/sleep.d that allow customizing the behavior of the system to suit everyone.