G. Pape

runit - a UNIX init scheme with service supervision

runit is a cross-platform Unix init scheme with service supervision, a replacement for sysvinit and other init schemes. It runs on GNU/Linux, *BSD, MacOSX, Solaris, and can easily be adapted to other Unix operating systems. If runit runs for you on any other operating system, please let me know.

Contribute to runit through GitHub runit.

runit is discussed on the <supervision@list.skarnet.org> mailing list. Please contact this list and not me privately.

To subscribe send an empty email to <supervision-subscribe@list.skarnet.org>.

Mailing list archives are available at skarnet.org, and mail-archive.com.

The program runit is intended to run as Unix process no 1, it is automatically started by the runit-init -replacement if this is started by the kernel.

runit performs the system's booting, running and shutting down in three stages:

Stage 1:
runit starts and waits for it to terminate. The system's one time initialization tasks are done here. has full control over to be able to start an emergency shell in case the one time initialization tasks fail.
Stage 2:
runit starts which should not return until the system is going to halt or reboot; if it crashes, it will be restarted. Normally, runs runsvdir. In Stage 2 runit optionally handles the INT signal (ctrl-alt-del keyboard request on Linux/i386).
Stage 3:
If runit is told to halt or reboot the system, or Stage 2 returns without errors, it terminates Stage 2 if it is running, and runs . The systems tasks to shutdown and halt or reboot are done here.

These are working examples for Debian sarge: /etc/runit/1, /etc/runit/2, /etc/runit/3.

The program runit-init is intended to replace . The command tells runit to halt the system, and to reboot. Runlevels are handled through the runsvdir and runsvchdir programs. Service dependencies are resolved automatically.

runit is optimized for reliability and small size. The amount of code in process no 1 should be minimal.

See How to install runit for installing runit, and How to replace init for configuring runit to run as process no 1. See How to use with current init if you want to use runit without replacing the current init scheme. Please read the list of Frequently asked questions with answers.

The following distributions are known to include or package runit:

Debian GNU/Linux (as alternative init scheme)
FreeBSD
OpenBSD
NetBSD
Ubuntu (as alternative init scheme)
Gentoo
Linux from Scratch
T2
ArchLinux
Void Linux (as default init scheme)
Artix Linux (as alternative init scheme)
antiX Linux (as alternative init scheme)
Debian GNU/Hurd

If you know of more distributions, please let me know.

runit in use: I replaced sysvinit successfully with runit on several server systems and a laptop running Debian/GNU Linux sarge, woody, and potato. Here is an example:

 # strings /proc/1/exe |grep Id
 $Id: runit.c,v 1.7 2002/02/13 09:59:52 pape Exp $
 # uptime
 11:59:13 up 365 days, 23:22, 3 users, load average: 0.01, 0.02, 0.00
 # ps axuw |head -n20
 USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
 root 1 0.0 0.0 20 16 ? S 2002 0:07 runit
 root 2 0.0 0.0 0 0 ? SW 2002 0:00 [keventd]
 root 3 0.0 0.0 0 0 ? SWN 2002 0:51 [ksoftirqd_CPU0]
 root 4 0.0 0.0 0 0 ? SW 2002 144:38 [kswapd]
 root 5 0.0 0.0 0 0 ? SW 2002 0:08 [bdflush]
 root 6 0.0 0.0 0 0 ? SW 2002 7:24 [kupdated]
 root 168 0.0 0.0 1652 168 ? S 2002 0:27 /usr/sbin/cron
 root 174 0.0 0.0 36 24 ? S 2002 1:06 runsvdir /var/service log: ...............................................................................................
 root 176 0.0 0.0 20 20 ? S 2002 0:00 runsv qmail-send
 root 177 0.0 0.0 20 20 ? S 2002 0:00 runsv getty-5
 root 178 0.0 0.0 20 20 ? S 2002 0:00 runsv getty-4
 root 179 0.0 0.0 20 20 ? S 2002 0:00 runsv getty-3
 root 180 0.0 0.0 20 20 ? S 2002 0:00 runsv getty-2
 root 182 0.0 0.0 20 20 ? S 2002 0:00 runsv socklog-unix
 root 183 0.0 0.0 1256 4 tty5 S 2002 0:00 /sbin/getty 38400 tty5 linux
 root 184 0.0 0.0 1256 4 tty3 S 2002 0:00 getty 38400 tty3 linux
 root 185 0.0 0.0 20 20 ? S 2002 0:00 runsv socklog-klog
 root 186 0.0 0.0 20 20 ? S 2002 0:00 runsv ssh
 root 187 0.0 0.0 1256 4 tty4 S 2002 0:00 getty 38400 tty4 linux
 # pstree
 runit-+-bdflush
 |-cron
 |-gcache
 |-keventd
 |-ksoftirqd_CPU0
 |-kswapd
 |-kupdated
 `-runsvdir-+-runsv-+-multilog
 | `-qmail-send-+-qmail-clean
 | |-qmail-lspawn
 | `-qmail-rspawn---qmail-remote
 |-4*[runsv---getty]
 |-2*[runsv-+-multilog]
 | `-socklog]
 |-runsv-+-multilog
 | `-sshd-+-sshd---sshd---bash---bash---pstree
 | `-sshd---sshd---rsync
 |-runsv---clockspeed
 |-runsv-+-dnscache
 | `-multilog
 |-runsv---apache-ssl-+-9*[apache-ssl]
 | |-gcache
 | `-4*[multilog]
 |-7*[runsv-+-multilog]
 | `-tcpserver]
 |-4*[runsv-+-multilog]
 | `-tinydns]
 |-runsv---uncat
 |-2*[runsv-+-multilog]
 | `-tcpsvd]
 |-runsv-+-svlogd
 | `-tcpsvd-+-smtpfront-qmail
 | `-smtpfront-qmail---qmail-queue
 `-runsv-+-svlogd
 `-tcpsvd---bincimap-up---bincimapd

See https://smarden.org/runit/ for recent information.

Gerrit Pape <pape@smarden.org>

URL: https://smarden.org/runit/

⇱ runit - a UNIX init scheme with service supervision

runit - a UNIX init scheme with service supervision