When running 'dnf update' the system will only keep 3 of the previous kernel versions installed. Once I attempt to install the 4th update then dnf wants to remove the oldest installed kernel. How can I increase or decrease the number of available/installed kernels?
Edit the file '/etc/dnf/dnf.conf', changing the numeric value in
installonly_limit=3 to a number of your choosing.
Be aware that if you increase the number too high then you run the risk of filling up the /boot partition.