OpenRC

Quick-Start Information

Alpine Linux uses OpenRC for its init system.

The following commands are available to manage the init system:

• Basics:

rc-update add <service> <runlevel>

rc-update del <service> <runlevel>

rc-service <service> <start stop restart> # ⇔ /etc/init.d/service <start stop restart>

• To check services and their set runlevels:

rc-status

• To change to a different runlevel:

openrc <runlevel>

• Reboot/Halt/Poweroff: (And their equivalent from traditional GNU/Linux systems)

reboot # ⇔ shutdown now -r

halt # ⇔ shutdown now -H

poweroff # ⇔ shutdown now -P

Available Runlevels

The available runlevels are:

• default - Used if no runlevel is specified. (This is generally the runlevel you want to add services to.)
• hotplugged
• manual

The special runlevels are:

• sysinit - Brings up system specific stuff such as /dev, /proc and optionally /sys for Linux based systems. It also mounts /lib/rc/init.d as a ramdisk using tmpfs where available unless / is mounted rw at boot. rc uses /lib/rc/init.d to hold state information about the services it runs. sysinit always runs when the host first starts and should not be run again.
• boot - Generally the only services you should add to the boot runlevel are those which deal with the mounting of filesystems, set the initial state of attached peripherals and logging. Hotplugged services are added to the boot runlevel by the system. All services in the boot and sysinit runlevels are automatically included in all other runlevels except for those listed here.
• single - Stops all services except for those in the sysinit runlevel.
• reboot - Changes to the shutdown runlevel and then reboots the host.
• shutdown - Changes to the shutdown runlevel and then halts the host.

rc-update usage

Usage: rc-update [options] add service <runlevel>
       rc-update [options] del service <runlevel>
       rc-update [options] show

Options: [suChqv]
  -s, --stack                       Stack a runlevel instead of a service
  -u, --update                      Force an update of the dependency tree
  -h, --help                        Display this help output
  -C, --nocolor                     Disable color output
  -v, --verbose                     Run verbosely
  -q, --quiet                       Run quietly

rc-status usage

Usage: rc-status [options] [runlevel1] [runlevel2] ...

Options: [aclrsuChqv]
  -a, --all                         Show services from all run levels
  -c, --crashed                     Show crashed services
  -l, --list                        Show list of run levels
  -r, --runlevel                    Show the name of the current runlevel
  -s, --servicelist                 Show service list
  -u, --unused                      Show services not assigned to any runlevel
  -h, --help                        Display this help output
  -C, --nocolor                     Disable color output
  -v, --verbose                     Run verbosely
  -q, --quiet                       Run quietly

rc-service usage

Usage: rc-service [options]

Options: [e:ilr:ChqVv]
  -e, --exists <arg>                tests if the service exists or not
  -i, --ifexists                    if the service exists then run the command
  -l, --list                        list all available services
  -r, --resolve <arg>               resolve the service name to an init script
  -h, --help                        Display this help output
  -C, --nocolor                     Disable color output
  -V, --version                     Display software version
  -v, --verbose                     Run verbosely
  -q, --quiet                       Run quietly

rc usage

Usage: rc [options]

Options: [a:o:s:SChqVv]
  -a, --applet <arg>                runs the applet specified by the next argument
  -o, --override <arg>              override the next runlevel to change into
                                    when leaving single user or boot runlevels
  -s, --service <arg>               runs the service specified with the rest
                                    of the arguments
  -S, --sys                         output the RC system type, if any
  -h, --help                        Display this help output
  -C, --nocolor                     Disable color output
  -V, --version                     Display software version
  -v, --verbose                     Run verbosely
  -q, --quiet                       Run quietly

Preventing slow services from delaying boot

Services that take a while to start will block the boot process until they complete. E.g.: iwd and networking might delay startup of an interactive system rather than start in the background.

This can be remedied using async services. See stacked runlevels for more details on this.

cgroups v2

Since openrc 0.51 cgroups v2, or "unified", is the default. You can enable hybrid cgroups v1 & v2 by editing /etc/rc.conf and setting rc_cgroup_mode="hybrid".

Then you should run

rc-service cgroups start

to take effect

and

rc-update add cgroups

to auto mount the cgroup filesystem on boot

See also

• Gentoo Wiki
• ArchWiki
• PostmarketOS Wiki