Introduction:
In order to debug some Zabbix problems here are some tools I gathered to help.

Requirements:
Installation of the package zabbix-get in the monitoring server
apt-get install zabbix-get
Installation of the package zabbix-agent in the monitored hosts.
apt-get install zabbix-agent

TIP: In order to programmatically (using bash for example) create scripts that monitor anything in remote hosts. Then:
– Install the package zabbix-agent in the watched hosts
– Configure /etc/zabbix/zabbix-agentd.conf to accept requests from the monitoring host (eg. Directive: ‘Server=myscripts.server.com’)
– Restart the zabbix agent(service zabbix-agent restart)
– Open their firewall on port 10050
– Install the package zabbix-get in the monitoring host(apt-get install zabbix-get)
– And use the same commands below inside your scripts to get this information required from the monitored hosts.

The following commands are given on the Zabbix server and the monitored host is eg. ‘examle1.myzabbix.com’

Commands:

Verify the availability of the zabbix agent on monitored host:
zabbix_get -s examle1.myzabbix.com -k agent.ping
Show the number of running processes on monitored host:
zabbix_get -s examle1.myzabbix.com -k proc.num[,,,]
Show the number of daemons up and running called ‘apache2’
zabbix_get -s examle1.myzabbix.com -k proc.num[,,,apache2]
Show free disk space mounted on ‘/’
zabbix_get -s examle1.myzabbix.com -k vfs.fs.size[/,free]