Just recently ZABBIX 4.0 came out, so I thought we will finally get ability to display values from multiole hosts on one graph – unfortunately not. BUT! There s a way to have it directly in ZABBIX dashboards – using Grafana.
Firtstly we need to install grafana – all stuff about how to do it is here: http://docs.grafana.org/installation/
Next we need to create grah with values (for instance “free memory”) from specific group, here is how to do it: http://docs.grafana-zabbix.org/guides/gettingstarted/
Next what we need to get the URL of the graph – from the specfic place (“Share” option of the graph):
Then you need to pick “Embed” and copy part of the URL from there:
Later create “URL” widget: