Systemd

cento is controlled using utility systemctl on operating systems and distributions that use the systemd service manager.

Upon successful package installation, the cento service is automatically started on the loopback interface. The service uses a configuration file that is located at /etc/cento/cento.conf and that is populated with some defaults during installation. The configuration file can be edited and extended with any configuration option supported by cento. A service restart is required after configuration file modifications.

The cento service is always started on boot by default. The service must be disabled to prevent this behavior.

The cento service configuration file

The configuration file is located at /etc/cento/cento.conf.

Controlling cento

To start, stop and restart the cento service type:

systemctl start cento
systemctl stop cento
systemctl restart cento

To prevent cento from starting on boot type:

systemctl disable cento

To start cento on boot, assuming it has previously been disabled, type:

systemctl enable cento

To check the status of the service, including its output and PID, type:

systemctl status cento

Instantiated cento services

There are circumstances under which multiple instances of the cento service may run on the same host. To manage a particular <instance> of the service, append an @<instance> to the cento service name.

Typically, <instance> corresponds to an interface name (e.g., eno1). This convention allows an easy identification of the purpose of each service. Nonetheless, any string is acceptable as value for <instance>.

The <instance> uniquely identifies a service and its corresponding configuration file that is located under /etc/cento/cento-<instance>.conf.

For example, to start two cento services, on interface eno1 and another on zero-copy interface eth1 respectively, one can create the following configuration files:

/etc/cento/cento-eno1.conf
/etc/cento/cento-zc:eth1.conf

And then start the services with:

systemctl start cento@eno1
systemctl start cento@zc:eth1

Optionally, one may want to start the services on boot with:

systemctl enable cento@eno1
systemctl enable cento@zc:eth1

The status of the services above can be controlled with:

systemctl status cento@eno1
systemctl status cento@zc:eth1