The items we've looked at so far allowed us to query the built-in capabilities of a Zabbix agent, query SNMP devices, and reuse data on the Zabbix server. Every now and then, a need arises to monitor something that isn't supported by Zabbix out of the box. The easiest and most popular method to extend Zabbix data collection is user parameters. They're commands that are run by the Zabbix agent and the result is returned as an item value. Let's try to set up some user parameters and see what things we should pay extra attention to.