Strange issue with booting XCP-NG

A Former User

@r1 I could try that, will update when that has been done...

A Former User

@r1 How do I boot in BIOS mode without a reinstall? Can that even be done, because I remember that when I installed xcp-ng I had to choose between BIOS or UEFI am I correct? (Could be something else though) otherwise if not I can give that a try.

r1

@appollonius I think it will depend on hardware settings. See if you have option to change the mode in motherboard settings?

I don't have physical hardware access to validate this as I mostly use nested virtualization but XCP-ng /boot has required files support both for UEFI and BIOS mode.

Maybe @stormi can confirm.

A Former User

@r1 If this could be confirmed I would be happy to test it, otherwise I'll have to do it when I have a new system.. Because I dont want to mess up the current one just yet

r1

@appollonius I don't think there is any harm. You will be either be able to boot or not. You can always switch back to old settings.

A Former User

@r1 Alright then I will give it a try somewhere today

stormi

Unless I'm mistaken, XCP-ng installed in UEFI mode won't boot in bios mode. There won't be anything written in the MBR.

A Former User

@stormi Ahh... So I would have to reinstall XCP-NG completely to be able to boot in BIOS?

stormi

@appollonius yes

A Former User

@stormi Damn... And that all to 'test' if the GPU is working in BIOS mode.

A Former User

Maybe I asked the wrong question here, but is the NVIDIA QUADRO P400 even supported? Maybe that could be an issue as well? If not I think I'll have to grab something like a Radeon WX2100..

stormi

It's not supported for vGPUs https://xcp-ng.org/docs/compute.html#vgpu but it should not prevent other uses of XCP-ng in theory.

A Former User

@stormi Ahh thanks for the webpage, though I still think BIOS mode wont fix this issue I believe.. So I will capture the serial output, to see what happens.

stormi

As I said (or tried to say), vGPU support has nothing to do with the ability to display the host console on screen.

stormi

So BIOS mode might help, but there's no guarantee.

A Former User

@stormi I wanna try this first so I can see what is going wrong in UEFI mode. So I can pass it on to you guys, so you might be able to fix this issue in UEFI mode. Because there might be other people running into this issue as well

A Former User

@r1 @stormi I digged alot today, I even exchanged the xen.gz with the possible fix that was mentioned above, where I discovered that it made my XCP-NG useless XD. Well I fixed it so I am back to normal now (hahaha). I read some more about this issue, but it could also be 'Grub' related. I have a source here: https://askubuntu.com/questions/825687/what-could-prevent-an-ubuntu-server-from-booting-without-a-vga-connected-monitor

And then specifically 'nomodeset' I haven't tested it yet because the grub.cfg is different from the default grub.cfg and I don't want to break things again..., but could that be a possible solution to this?

I have pasted the grub.cfg here, where could I put the 'nomodeset' option?

serial --unit=0 --speed=115200
terminal_input serial console
terminal_output serial console
set default=0
set timeout=5
if [ -s $prefix/grubenv ]; then
        load_env
fi

if [ -n "$override_entry" ]; then
        set default=$override_entry
fi

menuentry 'XCP-ng' {
        search --label --set root root-cybuwv
        multiboot2 /boot/xen.gz dom0_mem=4304M,max:4304M watchdog ucode=scan dom0_max_vcpus=1-16 crashkernel=256M,below=4G,console=vga vga=mode-0x0311 
        module2 /boot/vmlinuz-4.19-xen root=LABEL=root-cybuwv ro nolvm hpet=disable console=hvc0 console=tty0 quiet vga=785 splash plymouth.ignore-serial-consoles xen.pciback.hide=(0000:07:00.0)
        module2 /boot/initrd-4.19-xen.img
}

r1

@appollonius You can set nomodeset option at the end of line which starts with module2 /boot/vmlinuz-4.19-xen.

With other user it did no make any difference.

A Former User

@r1 Didn't work for me either.... Well I think this is then to stop the troubleshooting as I have no idea where the problem lies and we tried everything. When the monitor has been connected XCP-NG actually sees the GPU so I think it has something to do with the System parameters in UEFI or GRUB. But time will tell if someone else finds a potential solution to this...

A Former User

Well I just had some time to reinstall xcp-ng in LEGACY BIOS MODE but unfortunately this didnt solve anything and the problem persists...