Service Management
6.1 Types of services
System V services
Managed by System V init scripts
Scripts are stored in /etc/init.d
xinetd services
Services started by the xinetd daemon.
xinetd service control files located in /etc/xinetd.d
Defaults for xinetd set in /etc/xinetd.conf
xinetd itself is a System V service.
init services
Configured in /etc/inittab.
Provides respawn capability if service dies.
6.2 Management tools
System V services
service - Start/Stop services (CLI).
Example: To restart Apache:
service httpd stop
service httpd start
or
service httpd restart
chkconfig - Configure services by runlevel (CLI). Doesn't affect currently running services. Defaults to runlevels 3,4, and 5 if none specified.
To enable Apache on runlevels 3, 4, and 5:
chkconfig httpd on # If runlevels aren't specified, default is 345
To enable Apache only on runleves 3 & 5:
chkconfig --level 35 httpd on
ntsysv - Configure services by runlevel (TUI).
Default is to configure current run level. Use "--level" option to specify a different runlevel.
tksysv - Configure services by runlevel (GUI) (Deprecated).
xinetd services
chkconfig - Configures running services. Takes effect immediately on xinetd services.
To start vsftp:
chkconfig vsftp on
Edit service configuration file in /etc/xinetd.d/ directly. To enable, specify "disable = no". To disable, specify "disable = yes". After changing file, xinetd must either be given a USR2 signal so it re-reads it's configuration file or be restarted.
killall -USR2 xinetd
init services
The only way to modify init based services is to edit /etc/inittab. After modifying the file, activate the changes by executing "init q".