YaST2 Runlevel Editor Configuration Tool
Purpose
- setting default runlevel
- setting which runlevels services run in
Pre-requisites
Runlevel editor strongly depends on SuSE Linux conventions. Expected
/etc/inittab format:
- Default runlevel: is read from line ^id:.:initdefault: where
it is supposed that default runlevel is at the place of .
- List of runlevels: It is supposed that runlevels are changed via
running script /etc/init.d/rc. So to get list of runlevels we search
for parameters given to this script, because this script expects runlevel name
as an argument. We search for:
/^[^#]..*\/etc\/init\.d\/rc ARGUMENT.
Current runlevel is read from output of /sbin/runlevel.
List of init scripts is obtained from /etc/init.d/. Some names
are skipped, because they are not init scripts: core, README, rc, rx,
*.rpm*, *.ba*, *~, ... . For each init script, comment is read and default
runlevels and description are taken from it. See
LSB for specification of init script comments. Current settings, which mean
list of runlevels service is started in is taken from /etc/init.d/rc?.d
subdirectories. E.g. if there is a script /etc/init.d/rc5.d/S08network
then it means that service network is started in runlevel 5.
Service status is obtained by running initscript status.
Functionality
Now as we have all settings read, we may change them. Changing default runlevel
is straightforward. Just pick a new value from combobox. Note that this setting
means which runlevel system switches to after boot!!! So this option has no
immediate effect.
Detailed service editation enable changing which runlevels service runs
in. Some special options are available:
FIXME: WILL WE USE START_VARIABLES?
- Reset to default which resets service to state after installation. If
service was installed disabled, it will be disabled after this action!
- Reset all services to default does the same for all services.
- Enable the service enables disabled service and lets it run in
runlevels default for it. If you want to know which runlevels are default to
service, look into its init script
(/etc/init.d/service_name_as_seen_in_runlevel_editor).
All above settings are saved after button [Finish] is pressed. But following
operations happen immediately:
- Start service
- Stop service
- Refresh status
Saving
Default runlevel is saved to the same place it was read from.
Services are saved using
/sbin/insserv -r servicename
/sbin/insserv servicename,start=list_of_runlevels