I have hosts with and without keys in /root/.ssh. I've noticed before some on screen feedback for SSH key generation on start up (first time.) But I am not sure what the catalyst is. I have looked in /root/anaconda-ks.cfg and don't see anything different that could lead to this.
What was chosen/enabled for the servers that do versus the ones that do not?
Note: I know I can do it manually -- I am just looking to understand when / how it is inconsistently generated.