rcS After the installation of an Ubuntu system you should change the settings in /etc/defaut/rcS . Change the clock settings, if you are using UTC for the hardware clock, enable verbose logging during the boot process and enable the automatic check for fileystems if an error occures.
# assume that the BIOS clock is set to UTC time (recommended)
# be more verbose during the boot process
# automatically repair filesystems with inconsistencies during boot
grub You should also change the settings […]