Freedom251 › Process Monitoring Software
runit
What runit is
runit is a free Unix init scheme that supervises services and can replace sysvinit or other init schemes. It runs on GNU/Linux, *BSD, MacOSX, and Solaris, and can be adapted to other Unix systems. As process 1, it handles boot, normal operation, and shutdown in three stages. Its runsv component starts a service's run program and restarts it if it exits; optional finish programs and log services are also supported. The sv utility reports status and provides commands to start, stop, restart, pause, or signal supervised services. For logging, svlogd can filter messages and write automatically rotated logs. The chpst utility changes process state and can set resource limits, including memory, open files, process count, output size, core size, and CPU time. runsvdir can start and monitor runsv processes for up to 1,000 service subdirectories. runit can also supervise services alongside an existing init scheme without replacing it. The maker provides source and installation instructions, including manual installation without root access. UDP logging is documented as unreliable and limited to private networks.
Who it suits
runit suits Unix system administrators who want service supervision, process controls, and log handling. It can also be used alongside a system's current init scheme rather than replacing it.
What it does well
- Restarts services when their run program exits.
- Provides commands to control supervised services.
- Supports resource limits through chpst.
- Can supervise up to 1,000 service subdirectories.
- Manual installation without root access is documented.
What to know first
- UDP logging is unreliable outside private networks.
- Installation is provided from source.
- Other Unix systems may require adaptation.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| runit | No commercial limits stated | Free |
As smarden.org lists them, read 2 Oct 2026. The maker's own page has the final word.
Getting started
- Visit the runit website for the source archive and installation instructions.
- Compile and install runit, using the manual installation instructions if needed.
- Set up runit as the init scheme or configure its supervision alongside the current init scheme.
- Use runsv and sv to supervise and control services.
Verdict
runit provides init and service-supervision tools across several Unix systems, with an option to use its supervision without replacing the current init scheme. It is free, and its documented UDP logging limit is worth noting.
Questions
How much does runit cost?
The listed plan is free, with no commercial limits stated.
Which operating systems does runit support?
It runs on GNU/Linux, *BSD, MacOSX, and Solaris, and can be adapted for other Unix systems.
Can runit work without replacing the current init scheme?
Yes. Its documentation covers using service supervision alongside the system’s current init scheme.
How does runit restart services?
runsv starts a service’s run program and restarts it if it exits. An optional finish program and log service are also supported.
Does runit provide log handling?
svlogd can filter log messages and write them to automatically rotated logs. Its documentation warns that UDP logging is unreliable and should be used only on private networks.
How can I install runit?
The maker provides a source archive and compile-and-install instructions, including manual installation without root access.
Facts from runit's own pages
- Automatic discovery
- A symlink from /service to a service directory makes runit discover and start that service, typically within five seconds. · smarden.org, 15 Oct 2026
- Boot lifecycle
- As process 1, runit handles booting, normal operation and shutdown in three stages. · smarden.org, 2 Oct 2026
- Current upstream version
- The official install page names version 2.3.1 as the downloadable release. · smarden.org, 15 Oct 2026
- Debian licence record
- Debian records the upstream runit files as copyright Gerrit Pape and licensed BSD-3-Clause. · sources.debian.org, 15 Oct 2026
- Dependency handling
- Many dependencies are handled because a dependent service exits until its prerequisite is available, after which runsv retries it. · smarden.org, 15 Oct 2026
- Distribution availability
- The maker lists Debian, FreeBSD, OpenBSD, NetBSD, Ubuntu, Gentoo, Arch Linux, Void Linux and other distributions as including or packaging runit. · smarden.org, 2 Oct 2026
- Distribution packaging
- Void Linux packages runit 2.3.1 with a GNU make build and BSD-3-Clause licence metadata. · github.com, 15 Oct 2026
- Documentation
- The source distribution includes a doc directory and man directory, while the website links to manuals for each major command. · smarden.org, 15 Oct 2026
- Explicit dependencies
- For services needing ordered startup or shutdown, administrators place sv commands in run and finish scripts. · smarden.org, 15 Oct 2026
- Foreground requirement
- A supervised daemon must stay in the foreground, with the run script normally using exec to replace the shell. · smarden.org, 15 Oct 2026
- Independent adoption
- Wikipedia lists Void Linux, antiX and Dragora as distributions using runit as their default init system. · en.wikipedia.org, 15 Oct 2026
- Independent alternatives
- AlternativeTo lists runit as free and open source and shows more than ten alternatives including Dinit, OpenRC, systemd, sysvinit and s6. · alternativeto.net, 15 Oct 2026
- Independent architecture detail
- Wikipedia says stage 2 launches runsvdir, which creates a watchdog per service and restarts daemons that die. · en.wikipedia.org, 15 Oct 2026
- Independent description
- Wikipedia describes runit as a daemontools reimplementation that initializes, supervises and terminates Unix-like system processes. · en.wikipedia.org, 15 Oct 2026
- Installation
- The maker provides a source archive and instructions to compile and install runit, including manual installation without root access. · smarden.org, 2 Oct 2026
- Installation method
- The official installation downloads runit-2.3.1.tar.gz, compiles it and installs the programs with package/install. · smarden.org, 15 Oct 2026
- Licence
- runit is free software under a three-clause BSD-like licence. · smarden.org, 15 Oct 2026
- Limit: migration risk
- The replacement guide advises keeping an alternate boot method and restoring the former init if migration fails. · smarden.org, 15 Oct 2026
- Limit: portability work
- Although stage 2 is portable, the maker says stages 1 and 3 must be adapted to each operating system. · smarden.org, 15 Oct 2026
- Limit: service authoring
- Using runit requires administrators to create and maintain executable per-service scripts rather than conventional /etc/init.d scripts. · smarden.org, 15 Oct 2026
- Logging
- runsv can supervise a separate logging process and connect the service output to it without requiring both processes to restart together. · smarden.org, 15 Oct 2026
- Log transport limit
- svlogd documentation warns that UDP logging is unreliable and should be used only in private networks. · smarden.org, 2 Oct 2026
- Maker identity
- The official pages identify Gerrit Pape as the project contact and maintainer. · smarden.org, 15 Oct 2026
- Manual installation
- A non-root installation can compile and place binaries in a user's own bin directory, with documentation and man pages supplied in the source tree. · smarden.org, 15 Oct 2026
Where runit stands on Freedom251
- Process Monitoring Software#3 of 26