Spice console issues with RHEL/CentOS 7 instances ?

After I deployed Openstack Icehouse we did notice spice html5 proxy console issues in particular with CentOS 7 and RHEL 7 guests. Those guest consoles did show issues with the character echoing, you where not able to see what you have typed inside the terminal. I did track this issue down to  a spice html5 proxy issue whenever the guest is using a frame buffer enable console. After I did disable the frame buffer mode and switched the console to a text mode, the guest console was finally usable. Here the instructions :

Please add inside the /etc/default/grub config file the option “nofb nomodeset” to the GRUB_CMDLINE_LINUX variable and regenerate the grub2 config.

  • Tested configuration /etc/default/grub :
GRUB_TIMEOUT=1
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL="serial console"
GRUB_SERIAL_COMMAND="serial"
GRUB_CMDLINE_LINUX="console=ttyS0 console=tty0 crashkernel=auto vconsole.keymap=us nofb nomodeset"
GRUB_DISABLE_RECOVERY="true"
  • Rebuilt grub2 config

grub2-mkconfig -o /boot/grub2/grub.cfg

After the mandatory instance reboot the console will boot in text mode only and not using any frame buffer graphic device. The console should work as desired at this point.