So this one is pretty simple. However, I found a lot of misinformation along the way, so I figured that I would jot the proper (and most simple) process here.
Symptoms: a RHEL (or variant) VM that takes a very long time to boot. On the VM console, you can see the following output while the VM boot process is stalled and waiting for a timeout. Note that the message below has nothing to do with cloud init, but its the output that I have most often seen on the console while waiting for a VM to boot.
[106.325574} random: crng init done
Note that I have run into this issue in both OpenStack (when booting from external provider networks) and in KVM.
Upon initial boot of the VM, run the command below.
Seriously, that’s it. No need to disable or remove cloud-init services. See reference.