Linux VM (Ubuntu 22.04) - Grub-Menu invisible

KPS

Hi!

I am having a problem with linux VMs, that are not showing grub.
The console of the VM is black until the VM does really start.

What I tried:

Changed grub-config to:

GRUB_TIMEOUT=5
GRUB_TERMINAL=console

and

GRUB_TERMINAL="serial"
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"

Can you give me a hint on how to solve this?

Best wishes

GuillaumeHullin

Hi,
Have you run sudo update-grub after changing your configuration?

KPS

@GuillaumeHullin said in Linux VM (Ubuntu 22.04) - Grub-Menu invisible:

Hi,
Have you run sudo update-grub after changing your configuration?

Yes, I did

GuillaumeHullin

2 ideas:

What is the value of GRUB_TIMEOUT_STYLE?
Do you have a GPU connected? it's a shot in the dark but I got this kind of issue because of GPU drivers... but on bare-metal machines

GuillaumeHullin

I'm not sure to why you are setting up serial connection?

@KPS said in Linux VM (Ubuntu 22.04) - Grub-Menu invisible:

GRUB_TERMINAL="serial"
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"

I'm pretty new on XCP-ng... but I'm pretty sure the "console" of a VM is not a "serial console".

FYI, this is my /etc/default/grub

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
GRUB_CMDLINE_LINUX=""

KPS

@GuillaumeHullin
This was just something, I found while googeling...
I did use your config, but still:

Black screen instead of the boot-menu.

KPS

@GuillaumeHullin said in Linux VM (Ubuntu 22.04) - Grub-Menu invisible:

GRUB_TIMEOUT_STYLE

I did change GRUB_TIMEOUT_STYLE from "hidden" to "timeout".
Now, the system is counting down from 5 to 1 (on a screen, where the rest is black), but the menu is still missing

DustinB

@KPS Are you geographically separated from your XCP-ng hosts? I've noticed from time to time due to internet latency that I don't always see the grub menu.

GuillaumeHullin

@KPS said in Linux VM (Ubuntu 22.04) - Grub-Menu invisible:

GRUB_TIMEOUT_STYLE

Set it to menu

If ‘GRUB_TIMEOUT_STYLE’ is set to ‘countdown’ or ‘hidden’, the timeout is instead counted before the menu is displayed.
Source: https://www.gnu.org/software/grub/manual/grub/html_node/Simple-configuration.html

KPS

@GuillaumeHullin
That was the trick!

GRUB_TIMEOUT_STYLE="menu" did solve it!

GuillaumeHullin

@KPS Glad to hear