ubuntu boot startup debugging

• After BIOS press "ESC" repeatedly to enter Grub menu
• (Press key down to select the lastest Ubuntu kernel without rescue mode)
• Press "e"
• Find the line starting with "linux" and remove from the end "quiet splash vt.handoff=xxx"
• Hit F10
• You can now see all startup output

Boot without graphical interface

• Same as above, but add "single" at the end of the line starting with "linux"

Make changes permanent

• vi /etc/default/grub
  • remove / comment out "quiet splash"
  • #GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
    GRUB_CMDLINE_LINUX_DEFAULT=""
• update-grub
• reboot