Sorted:

What are the common issues and troubleshooting methods for Nagios?

How is Nagios configured and set up?

Is it possible for Nagios to integrate with other systems?

What are the advantages and disadvantages of Nagios?

How does Nagios handle alerts and notifications?

How can monitoring data from Nagios be visualized and reports generated?

How does the Cacti system monitor network devices and servers?

What are the main functions of the Cacti system?

How does Nagios handle abnormal situations and recover from failures?

How to install and configure the Cacti system?