Ubuntu in VirtualBox

I use Ubuntu Server in VirtualBox for all sorts of development and testing and two items that always bug me with new installs is the slow frame buffer updates and a warning on startup that piix4_smbus ... SMBus base address in uninitialized. Both can be fixed by updating /etc/modprobe.d/blacklist.conf. Add the following to the end of that file:-

# don't use vga16 framebuffer
blacklist vga16fb

# don't probe for i2c_piix4
blacklist i2c_piix4