Can't upload it right now but you need a Zabbix Server (http://www.zabbix.com/) somewhere set up. Then download the Source Code and compile the Agent on any Raspberry Pi (did it on a RPi B), but just the agent as described here https://www.zabbix.com/documentation/3.2/manual/installation/install
In Zabbix I created a Template for Raspberry Pi's and added an item with the following details:
I refresh all values every 60sec, save history for 7 days and trend for 365 days.
After that I added the Slice as a host and assigned the template.
I copied the compiled agent to the HDD inside the Slice.
I created a shell script that will restart the agent in case it dies:
while [ /bin/true ]
/var/media/Slice/.zabbix/agent/zabbix_agentd -c /var/media/Slice/.zabbix/zabbix_agentd.conf -f
And added the script run with nohup to /storage/.config/autostart.sh:
rm /var/media/Slice/.zabbix/nohup.out &> /dev/null
nohup /var/media/Slice/.zabbix/start_agentd.sh &
For everyone interested my precompiled agent: http://myserv.cloud/f/b46ea8ef64/