My old system has been working great since 2018. I want to experiment with a new Rasberry pi 5 server and openHAB 5. How do I configure it to where it will not conflict or damage my old system? I realize I need to use another unique static IP address. And….There is a place where I can change log-in name from “openHABian to something like “test-openhabian”, but the user Interface (UI) and things like that keep take me to the old system. I don’t want to brick my old setup.
They are running on separate machines so there is next to zero chance your OH 5 can do any damage whatsoever to the old system.
You are probably using http://openhabian:8080 to access the UI. Use http://<ip address of the RPi 5>:8080 to access the UI for the new instance.
Or change the hostname of the RPi 5. I don’t think there is an option to do that in openhabian-config though. You’ll have to do that manually. Search for “change hostname debian” to verify, but I think you just need to modify /etc/hostname.
Then you can use http://<new hostname>:8080 to access the new OH install.