Where can I locate the file that handles power configurations and HDD parameters?

Question

I'm trying to compare the differences between how power management is handled on battery and when plugged in. As a result I want to look at the config files for the two instances. Thanks in advance.

Answer 1

hdparm is the command to get and set hard disk parameters.

hdparm is a command line utility for the Linux and Windows operating systems to set and view ATA hard disk drive hardware parameters. It can set parameters such as drive caches, sleep mode, power management, acoustic management, and DMA settings. GParted and Parted Magic both include hdparm.

hdparm has to be run with root privileges, otherwise it will either not be found or the requested actions will not be executed properly.

Some examples:

Display information of the hard drive:

hdparm -I /dev/sda

Turn on DMA for the first hard drive:

hdparm -d1 /dev/sda

Test cache read performance of the first hard drive:

hdparm -t /dev/sda

Enable energy saving spindown after inactivity (24*5=120 seconds):

hdparm -S 24 /dev/sda

To retain hdparm settings after a software reset, run:

hdparm -K 1 /dev/sda

Enable read-ahead:

hdparm -A 1 /dev/sda

If the disk is constantly too noisy, you can change its acoustic management at the cost of read/write performance:

hdparm -M 128 /dev/sda

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External links with more examples:

• Chamith
• ThinkWiki
• Documentaton for /proc/sys/vm

Answer 2

This is not what you are looking for but if you are trying to control your laptop, you can always install Jupiter

sudo apt-add-repository ppa:webupd8team/jupiter
sudo apt-get update
sudo apt-get install jupiter

Source