1

I had 4 partitions on my HDD, C, D and 2 reserved, I had GPT style partition table.

To install Ubuntu I shrank D from 338 to 278 GB, started installing Ubuntu on remaining approx 60 GB, from which I used 59.7 GB for installation and the rest for Reserve boot bios type what it wants to install GRUB.

All installation went successfully but now it's directly booting into Ubuntu 20.04, not showing the GRUB menu to make selection between installed OSes.

How can I fix it?

Zanna
  • 72,312
Oralover
  • 13

2 Answers2

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Edit your /etc/default/grub as such.
Edit or replace these lines;
GRUB_DEFAULT=0
#GRUB_DEFAULT=saved
#GRUB_SAVEDEFAULT=true
#GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10

Commit the changes then don't forget to... sudo update-grub then reboot.

darth_epoxy
  • 699
0

In Ubuntu 20.04.2 with MATE desktop, GRUB_TERMINAL=console was what helped reveal the grub boot menu. GRUB_TIMEOUT_STYLE was set to menu but Ubuntu or MATE desktop graphical boot menu was hiding the grub menu.

So these in /etc/default/grub:

GRUB_TIMEOUT=3
GRUB_TIMEOUT_STYLE=menu
GRUB_TERMINAL=console

As always, don't forget sudo update-grub.

If Windows 10 doesn't show up in grub menu, os-prober auto-detected my windows install and then update-grub brought it back. Shew, back to dual-boot. Worked just like you'd want.

Marc Compere
  • 848