Adding and quiting services with chkconfig

Adding and quiting services with chkconfig

This implementation of chkconfig was inspired by the chkconfig command present in the IRIX operating system. Rather than maintaining configuation information outside of the /etc/rc[0-6].d hierarchy, however, this version directly manages the symlinks in /etc/rc[0-6].d.

In Redhat Linux you have a powerfull tool called chkconfig, you can list all the services with:
chkconfig --list
To see the services started in runlevel 3:
chkconfig --list | grep 3:on

To turn off a service in all the runlevels:
chkconfig pcmcia off

Turn off a service in a desired runlevel:
[root@monitor1]# chkconfig --list | grep hpoj
hpoj 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@monitor1]# chkconfig --level 3 hpoj off
[root@monitor1 rc3.d]# chkconfig --list | grep hpoj
hpoj 0:off 1:off 2:on 3:off 4:on 5:on 6:off


If you want to add a new service, you created the /etc/rc.d/init.d/ file and now you wans to manage the service, configure it to start and stop on desired runlevels.

Edit the /etc/rc.d/init.d/service-name file, and add this line on the top:
#!/bin/bash
# chkconfig: 2345 55 25
# description: A service that does powerful things
#

This is a description of what this line does:
# chkconfig: 2345 55 25
  | | |
  | | priority for kill scripts
  | |
  | priority for start scripts
  |
  run levels at which to start service

Then execute, for example, adding the qmail service:
[root@monitor1 init.d]# chkconfig --add qmail
[root@monitor1 init.d]# chkconfig --list qmail
qmail 0:off 1:off 2:off 3:on 4:off 5:on 6:off

Now configure it to start on desired runlevels !