Services and Daemons
indexterm:[services configuration] Maintaining security on your system is extremely important, and one approach for this task is to manage access to system services carefully. Your system may need to provide open access to particular services (for example, `httpd` if you are running a web server). However, if you do not need to provide a service, you should turn it off to minimize your exposure to possible bug exploits.
This chapter covers the configuration of the services to be run when a system is started, and provides information on how to start, stop, and restart the services on the command line using the [application]*systemctl* utility.
Keep the system secure
When you allow access for new services, always remember that both the firewall and [application]*SELinux* need to be configured as well. One of the most common mistakes committed when configuring a new service is neglecting to implement the necessary firewall configuration and SELinux policies to allow access for it.
Configuring Services
indexterm:[systemctl,services configuration]indexterm:[services configuration,systemctl] To allow you to configure which services are started at boot time, {MAJOROS} is shipped with the [application]*systemctl* command line tool.
Do not use the ntsysv and chkconfig utilities
Although it is still possible to use the [application]*ntsysv* and [application]*chkconfig* utilities to manage services that have init scripts installed in the `/etc/rc.d/init.d/` directory, it is advised that you use the [application]*systemctl* utility.
Enabling the irqbalance service
To ensure optimal performance on POWER architecture, it is recommended that the `irqbalance` service is enabled. In most cases, this service is installed and configured to run during the {MAJOROSVER} installation. To verify that `irqbalance` is running, type the following at a shell prompt:
[command]#systemctl status irqbalance.service#
Enabling the Service
To configure a service to be automatically started at boot time, use the [command]#systemctl# command in the following form:
systemctl enable service_name.service
The service will be started the next time you boot the system. For information on how to start the service immediately, refer to xref:Services_and_Daemons.adoc#s3-services-running-running[Running the Service].
Enabling the httpd service
Imagine you want to run the Apache HTTP Server on your system. Provided that you have the [package]*httpd* package installed, you can enable the `httpd` service by typing the following at a shell prompt as `root`:
~]# systemctl enable httpd.service
Disabling the Service