Suspend-On-Idle Daemon for GNU/Linux Power Management
Circadian is a background daemon/service for triggering suspend/sleep/hibernate automatically when a computer is idle.
It is primarily for stationary devices with permanent power (i.e. desktops, servers, media centers).
Circadian uses a suite of 'idle heuristics' to determine when a system is idle. These include:
- User activity in X11 (keyboard, mouse, full-screen playback)
- User activity in terminals (typing in PTY/SSH session)
- Open SSH connections
- Open SMB/Samba connections
- Active audio playback
- CPU usage below specified threshold
- Blacklisted processes
When all of its heuristics determine that your system has been idle for long enough, Circadian will execute a command. This is typically a simple power suspend, but it can be configured to any desired action.
Circadian can also schedule an automatic daily wakeup. Simply set a wake time in its configuration file and it will wake up once every day at that time (if not already awake). This allows an easy way to keep a machine updated and backed up, even if it is seldom used.
It can also execute a command when it detects that the system has woken up from sleep, regardless of why it woke up.
Circadian exists because modern Linux distros already support suspend-on-idle, but it is apparently a very buggy and unreliable domain. After you've followed your distro's advice of poking a handful of conf files, tweaking a few XML hierarchies, writing a few scripts, wafting the smoke of burning sage across your keyboard, suspending gem stones from your machine, and whatever else may be recommended... perhaps try Circadian.
Example use cases
- Gaming rig with noisy fans? Auto-sleep when idle!
- Storage/backup machine? Auto-wake, backup, and auto-sleep!
- Seldom used server, but needs to be available? Wake-on-LAN, and auto-sleep when no SSH connections!
- Wake up to your local music library? Auto-wake, play music, and auto-sleep!
- Media center that you only use in evenings? Sleep all day, auto-wake when you get home!
"Works for me". You try. You give feedback on GitHub, or to email@example.com.
- Download Circadian 0.6.0
$ sudo dpkg -i circadian_0.6.0-1_amd64.deb
Edit /etc/circadian.conf to configure. The default is to suspend with systemd after 2 hours of idle.
When you are happy with the config, continue:
$ sudo systemctl enable circadian $ sudo systemctl start circadian
Any other system with systemd
Install manually. It's easy.
$ git clone https://github.com/mrmekon/circadian.git $ cd circadian $ cargo build --release $ sudo cp target/release/circadian /usr/local/bin/ $ sudo cp resources/circadian.conf.in /etc/circadian.conf $ sudo cp resources/circadian.service /etc/systemd/system/ $ sudo systemctl enable circadian $ sudo systemctl start circadian
Follow systemd instructions, and port circadian.service to whatever format you want.
- Might need to install
- rustc + cargo (if building locally)
- Should already have
Auto-wake requires kernel support for the real-time clock (RTC). You can check for the file
/sys/class/rtc/rtc0/wakealarm. You probably have it.
- Should run as root, ideally from systemd.
- Config is in: /etc/circadian.conf (it is documented)
pkill -SIGUSR1 circadianwill dump info to syslog. Use that to see if it's working, or find out why it isn't sleeping.