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Name

runit - A PID 1 init daemon

Synopsis

runit

Description

runit must be ran as Unix PID 1. It performs the system’s booting, running, and shutdown in three stages:

1. runit runs /etc/runit/1 and waits for it to terminate. The system’s one time tasks are done here. /etc/runit/1 has full control of /dev/console to be able to start an emergency shell if the one time initialization tasks fail. If /etc/runit/1 crashes, or exits 100, runit will skip stage 2 and enter stage 3.
2. runit runs /etc/runit/2, which should not return until system shutdown; if it crashes, or exits 111, it will be restarted. Normally /etc/runit/2 starts runsvdir(8). runit is able to handle the ctrl-alt-del keyboard request in stage 2, see below.
3. If runit is told to shutdown the system, or stage 2 returns, it terminates stage 2 if it is running, and runs /etc/runit/3. The systems tasks to shutdown and possibly halt or reboot the system are done here. If stage 3 returns, runit checks if the file /etc/runit/reboot exists and has the execute by owner permission set. If so, the system is rebooted, it’s halted otherwise.

Ctrl-alt-del

runit only accepts signals in stage 2.

If runit receives the ctrl-alt-del keyboard request and the file /etc/runit/ctrlaltdel exists and has the execute by owner permission set, runit runs /etc/runit/ctrlaltdel, waits for it to terminate, and then sends itself a CONT signal. Signals

If runit receives a CONT signal and the file /etc/runit/stopit exists and has the execute by owner permission set, runit is told to shutdown the system.

if runit receives an INT signal, a ctrl-alt-del keyboard request is triggered.

See Also

runit-init(8), runsvdir(8), runsvchdir(8), sv(8), runsv(8), chpst(8), utmpset(8), svlogd(8)

Authors

Gerrit Pape pape@smarden.org
Frank Earl linusti@gmail.com