14.3 System Configuration via /etc/sysconfig
The main configuration of openSUSE is controlled by the
configuration files in /etc/sysconfig. The
individual files in /etc/sysconfig are only read by
the scripts to which they are relevant. This ensures that network
settings, for example, only need to be parsed by network-related scripts.
There are two ways to edit the system configuration. Either use the
YaST sysconfig Editor or edit the configuration files manually.
14.3.1 Changing the System Configuration Using the YaST sysconfig Editor
The YaST sysconfig editor provides an easy-to-use front-end to system
configuration. Without any knowledge of the actual location of the
configuration variable you need to change, you can just use the built-in
search function of this module, change the value of the configuration
variable as needed, and let YaST take care of applying these changes,
updating configurations that depend on the values set in
sysconfig and restarting services.
WARNING: Modifying /etc/sysconfig/* Files Can Damage Your Installation
Do not modify the /etc/sysconfig files if you lack
previous experience and knowledge. It could do considerable damage to
your system. The files in /etc/sysconfig include a
short comment for each variable to explain what effect they actually
have.
The YaST sysconfig dialog is split into three parts. The left part of
the dialog shows a tree view of all configurable variables. When you
select a variable, the right part displays both the current selection
and the current setting of this variable. Below, a third window displays
a short description of the variable's purpose, possible values, the
default value, and the actual configuration file from which this
variable originates. The dialog also provides information about which
configuration script is executed after changing the variable and which
new service is started as a result of the change. YaST prompts you to
confirm your changes and informs you which scripts will be executed
after you leave the dialog by selecting . Also
select the services and scripts to skip for now, so they are started
later. YaST applies all changes automatically and restarts any
services involved for your changes to take an effect.
14.3.2 Changing the System Configuration Manually
To manually change the system configuration, proceed as follows
-
Become root.
-
Bring the system into single user mode (runlevel 1) with
telinit 1.
-
Change the configuration files as needed with an editor of your
choice.
If you do not use YaST to change the configuration files in
/etc/sysconfig, make sure that empty variable
values are represented by two quotation marks
(KEYTABLE="") and that
values with blanks in them are enclosed in quotation marks. Values
consisting of one word only do not need to be quoted.
-
Execute SuSEconfig to make sure that the changes
take effect.
-
Bring your system back to the previous runlevel with a command like
telinit
default_runlevel. Replace
default_runlevel with the default runlevel
of the system. Choose 5 if you want to return to
full multiuser with network and X or choose 3 if
you prefer to work in full multiuser with network.
This procedure is mainly relevant when changing systemwide settings,
such as the network configuration. Small changes should not require
going into single user mode, but you may still do so to make absolutely
sure that all the programs concerned are correctly restarted.
HINT: Configuring Automated System Configuration
To disable the automated system configuration by SuSEconfig, set the
variable ENABLE_SUSECONFIG in
/etc/sysconfig/suseconfig to
no. Do not disable SuSEconfig if you want to use
the SUSE installation support. It is also possible to disable the
autoconfiguration partially.
