I have installed linux server with GRUB. It works fine with monitor connected. But if unplug monitor and reboot server - GRUB is not starting.
I have tried to load other linux (without GRUB) from USB stick - its booting fine without monitor.
I have tried many options (like
/etc/default/grub, but it useless because GRUB not starting at all. I have added
play command at the top of
/boot/grub/grub.cfg file. Tone was played with monitor connected but not played without monitor. So all options in
/boot/grub/grub.cfg file is useless because it not loaded.
The last option is to make dummy VGA cable to simulate monitor presence, but I still hope that the problem can solved without any "hardware" :)
What could be the problem? Is there any way to enable GRUB verbose logging on failed boot and read it after successful boot?