You can find instructions on Howtoforge for installing Zabbix 6 on Debian GNU/Linux 11.
How to install Zabbix 6 on Debian 11
Zabbix is a free and open-source software used to monitor several IT components, including networks, servers, virtual machines, and cloud services. It provides real-time monitoring metrics such as network utilization, CPU load, and disk space consumption. These metrics help the system administrators to check the current health of your IT infrastructure and detect problems with hardware or software components. Zabbix uses MySQL, PostgreSQL, or Oracle to store its collected data. Zabbix uses agent software on the monitored server to gather data and send it to the Zabbix server.
This tutorial will show you how to install the Zabbix monitoring server on Debian 11.
