Maybe a very simple question:
How do I suppress all boot messages from the startup, including the login messages?
To hide the login prompt run
systemctl disable getty@tty1.service
To hide boot messages on Raspberry Pi run
sudo sed -i -e 's/console=tty1/console=tty3/g' /boot/cmdline.txt
Note that these steps have to be applied after each Volumio update.
Thank you very much