Merge RRD files

Hi friends,

I’m trying to merge RRD files in order to keep historical data. I had to give up the host I was monitoring the service with and there are some days where I am completely missing data.
The check now has another host and service_name, but the metricnames are the same. So in theory it should be doable.

Are there any cli tools available to achieve this goal or do I have to look outside of check_mk? (google, or write something myself)

PS: I am using CMK Free 2.1.0p6 for these metrics in order to programmatically export them as PNG files.
PPS: Here is an example of why I want to get the perfdata back:

One way would be to export the old RRD and new RRD with “rrdtool dump” combine the resulting XML and recreate the RRD with “rrdtool restore”.
I don’t know if there exists any gui tool that does this process.

Hi, I found this script useful for this purpose: