How to log with maximum verbosity into both an instance's console.log and VNC console in Red Hat OpenStack Platform?

Issue

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How to log with maximum verbosity into both an instance's console.log and VNC console in Red Hat OpenStack Platform?

When instances are configured with the defaults such as Red Hat's cloud image, /proc/cmdline is configured with:

console=tty0 (...) console=ttyS0,115200n8

In this case, console.log (ttyS0) shows more detailed log output upon boot than what is printed to VNC via tty0. In specific scenarios upon instance boot this may suppress the display of specific prompts, e.g. in the case of file system corruption. The only way to interact with the instance in these cases is to go into the grub menu and remove console=ttyS0,115200n8.

• How can one have both console.log and the interactive console with the same degree of verbosity?
• Is this possible in OSP 10 (Newton) or in later versions of OpenStack Platform?