I was experimenting with applying two device templates to the same server to test how it handles the monitors added to the server. For example, I have a Linux server that has been collecting data for several weeks for just its typical monitors (disk space, cpu, memory, interface traffic, etc.). I recently created a new template containing a custom monitor for monitoring an apache webserver via SNMP (I have an agent that collects data and pushes it out to a unique SNMP OID). By taking this new template and applying (not Apply & Overwrite), the custom monitor adds itself successfully to the server without removing any of the previous monitors. However, when looking through the graphs for the other monitors, I notice that quite a bit of data is missing. The monitors continue to work normally, but any data up until that point for disk, cpu, and memory seem to be totally gone, while interface traffic data seems to be okay.

I realize that what I did with the custom monitor template is atypical, so I suspected something to mess up. I have no problem with the lost data, but I'm wondering if something like this could be prevented if I continue to create custom monitor templates and apply them to servers.

I noticed that when I added the template, given the way I had to configure it, the "Type" of the server changed and I had to go back and set it to "Linux." Is this what caused the data loss?

Thanks