21.5. chkconfig

The chkconfig command can also be used to activate and deactivate services. The chkconfig --list command displays a list of system services and whether they are started (on) or stopped (off) in runlevels 0-6. At the end of the list is a section for the services managed by xinetd.

If the chkconfig --list command is used to query a service managed by xinetd, it displays whether the xinetd service is enabled (on) or disabled (off). For example, the command chkconfig --list finger returns the following output:

finger          on

As shown, finger is enabled as an xinetd service. If xinetd is running, finger is enabled.

If you use chkconfig --list to query a service in /etc/rc.d, service's settings for each runlevel are displayed. For example, the command chkconfig --list httpd returns the following output:

httpd         0:off   1:off   2:on    3:on    4:on    5:on    6:off

chkconfig can also be used to configure a service to be started (or not) in a specific runlevel. For example, to turn nscd off in runlevels 3, 4, and 5, use the following command:

chkconfig --level 345 nscd off

Warning

Services managed by xinetd are immediately affected by chkconfig. For example, if xinetd is running, finger is disabled, and the command chkconfig finger on is executed, finger is immediately enabled without having to restart xinetd manually. Changes for other services do not take effect immediately after using chkconfig. You must stop or start the individual service with the command service daemon stop. In the previous example, replace daemon with the name of the service you want to stop; for example, httpd. Replace stop with start or restart to start or restart the service.