Curious, we stood up a new CentOS 7 Checkmk RE 1.6.0p13 instance several weeks back, and it’s working very well. No sign of this rrdtool error.
Only thought I have is if you installed the Checkmk RPM with “rpm” or with “yum”. Using the latter may bring in some dependency RPMs. Other than that, I’d keep looking through log messages.