[SOLVED] GRUB menu, one OS, how to show it

[Qqmike]

If you have only one OS, you will not see your GRUB menu upon (re-)booting, unless immediately after the POST you hit ESC repeatedly at just the right time(s) and get lucky and then the GRUB boot menu may appear. Of course, if you have only one OS, you may have no need to see any boot menu. That boot menu (with only one OS installed) shows you your Kubuntu (as "ubuntu"), an option to re-boot, Advanced Options, and an option to re-boot into your System firmware setup (firmware-UEFI-BIOS).

I have for the moment just one OS installed, do not see my GRUB boot menu upon booting, and noticed a statement I wasn't familiar with in my GRUB settings file, /etc/default/grub:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xe fefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"


If you want to always see your GRUB menu upon (re-)booting, simply edit that file, changing the line
GRUB_TIMEOUT_STYLE=hidden
to this:
GRUB_TIMEOUT_STYLE=menu
Then close the file /etc/default/grub, open Konsole and type the command
sudo update-grub
Then close all your open windows and re-boot to test it.

[Qqmike]

And
GRUB_TIMEOUT_STYLE=countdown
shows only the countdown in seconds (that you set with GRUB_TIMEOUT=[seconds]); does not show boot menu.

[papakanush]

Another way that I did it was to simply comment out the line: GRUB_TIMEOUT_STYLE=HIDDEN;

i.e.
#GRUB_TIMEOUT_STYLE=HIDDEN

then
sudo update-grub

Works for me.