Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [power-management]

Systems to manage power consumption, such as system suspension and hibernation, CPU speed adjustment, disk spindown, battery usage monitoring, …

This tag is about issues, procedures, and problems related to power aspect of the *nix system from power save, system idle time, hibernate, auto-shutdown and other related acpi subjects.

582 questions
48
votes
7 answers

Return value of current watt consumption on command line

Is there a way to return the current watt consumption on the command line? I have found about the powertop program, but have not seen a way to return the Watt consumption as a value to the command line. I'm thinking of some file that I can cat or…
please delete me
  • 2,539
13
votes
1 answer

Why does drive not enter standby mode when using hdparm -S

When reading the hdparm manual pages, it says that the -S value is used by the drive to determine how long to wait (with no disk activity) before turning off the spindle motor to save power When configuring my drives with hdparm -B 1 -K 1 -S…
Pro Backup
  • 4,924
9
votes
3 answers

How can I find out the estimated power use of my desktop computer?

Is there a way to get the computer power usage instead of battery load tracking (what for instance seemingly powertop does), which is obviously not too useful on desktops?
mbq
  • 193
6
votes
2 answers

Preventing battery from charging

I'm running on UPS power and would like to prevent the laptop's battery from charging, to increase the amount of power available to other devices. Is there a way to do this? update: The machine is a Dell Latitude D400. If people want more details,…
intuited
  • 3,538
5
votes
1 answer

Why is upower output different from /sys/class/power_supply contents?

I'm debugging a situation where the remaining battery percentage report is not accurate for my newly installed battery. Regarding the answer of my previous question, various tools query the battery information directly from the battery itself.…
ceremcem
  • 2,351
3
votes
0 answers

Set computer to suspend after a certain time when not logged in?

I realize that you can set the power preferences for when to shutdown, suspend, and spin down hard disks and so on. However, I find that seems to only work when I've logged in and then leave the computer - the power will suspend after the specified…
linstar
  • 753
2
votes
0 answers

Which daemon monitor the battery (and activity, etc.) and put the system to sleep when the proper conditions are met?

In almost all Linux distributions you can configure that when some conditions are met the computer will be put to sleep/hibernate. After some time of inactivity, or when the battery is low, etc.. As far as I understand, systemd just expose the…
hahalol9
  • 21
  • 1
2
votes
1 answer

Measuring the current or the power

Is there a way to measure the electric current or power of the whole computer or its components using software? Voltage can be measured, and I am wondering why not with the current/power.
sawa
  • 872
2
votes
1 answer

what does pm-suspend-hybrid do?

man says pm-suspend During suspend most devices are shutdown, and system state is saved in RAM. The system still requires power in this state. Most modern systems require 3 to 5 seconds to enter and leave suspend, and most laptops…
Tim
  • 101,790
1
vote
1 answer

system sleep takes a long time

I just upgraded to Debian GNU/Linux 11 (bullseye), from Debian 10. After the upgrade it is taking a long time to put the system to sleep. E.g. the command systemctl suspend, locks the session quickly but takes 30 seconds to put the system to sleep.…
ctrl-alt-delor
  • 27,993
1
vote
0 answers

Put a graphic card into low energy mode

I have a home PC server with a PCIe graphic card (not integrated into the CPU or motherboard). This graphic card has a fan to keep it cool which involve some noise, and the electric consumption seems not negligible (heat involve power). This server…
Gregory MOUSSAT
  • 1,138
1
vote
1 answer

What is "C sort order" in pm-action manpage?

From manpage pm-action(8): /etc/pm/sleep.d, /usr/lib/pm-utils/sleep.d Programs in these directories (called hooks) are combined and executed in C sort order before suspend and hibernate with as argument ´suspend´ or ´hibernate´.…
Tim
  • 101,790
1
vote
0 answers

Waking up laptop from cron

I want my laptop to wake up at 0300 even with the lid closed, check power & network status and perform certain functions if it is connected. There's rtcwake but I don't want to use it to suspend: I just want to use the lid. I looked through APM…
mikea
  • 151
1
vote
0 answers

Set the cpu frequency upon resuming from suspension?

On Ubuntu 14.04, I hope to set the cpu frequency upon resuming from suspension, so I created a file /etc/pm/sleep.d/20_cpu_freq with content: #!/bin/bash case $1 in resume) sudo cpufreq-set -f 1.60GHz -c0 sudo…
Tim
  • 101,790
0
votes
1 answer

"Linux 3.19 and onwards, we should look at `/sys/class/power_supply/BAT1/`"?

https://askubuntu.com/a/309146/ says: Now we are encouraged to use -> /sys/class/power_supply/BAT0. UPDATE: Linux 3.19 and onwards, we should look at the following directory -> /sys/class/power_supply/BAT1/ But on my NixOS: $ uname -a Linux o…
Tim
  • 101,790
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