Re: Choosing grub2 video modes

[Alex Regan]

Hi,

> > I'm confused about how to control the text video mode from grub. I've
> > seen references to GRUB_GFXMODE and gfxmode, but I don't understand how
> > it's set.
>
> gfxmode is interpreted by gfxterm console driver when it starts. If you
> are using plain console, it has no effect. To change resolution during
> run-time you would probably need to switch console driver to something
> else (see terminal_output command) and then back.
>
> > I've tried setting it using "set gfxmode=640x480" in
> > /boot/grub2/grub.cfg and other variations, but they seem to be ignored.
>
> This must be done before output is switched to gfxterm.
>
> > I've tried setting GRUB_GFXMODE=640x480 in /etc/default/grub then
> > recreating grub.cfg, but that also doesn't appear to work.
>
> You need to use GRUB_TERMINAL_OUTPUT=gfxterm for this to have any
> effect. Or load gfxterm manually in grub.cfg or at run-time.

I must not be understanding, because I've made a few other changes and 
it still doesn't work. Can you check my /etc/default/grub file and see 
what further changes need to be made?

GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT=gfxterm
GRUB_TERMINAL=gfxterm
GRUB_CMDLINE_LINUX="rd.md.uuid=bde3f430:15091bce:874aaa0e:e48f341a 
rd.md.uuid=921fb4bb:6329d29b:734b1584:7f4d3dba "
GRUB_DISABLE_RECOVERY="true"
GRUB_GFXMODE=800x600x32
GRUB_GFXPAYLOAD=800x600x32
GRUB_GFXPAYLOAD_LINUX=800x600x32

When booting, it also prints some kind of "error" message but it goes to 
fast to see what's being printed. Is this info saved anywhere, or is it 
possible to store it or pause it to view? Or perhaps you can identify it 
from some incorrect setting in the file?

I'm pretty much grasping at straws now because there is just so much 
information, so much has changed, and there seems to be no definitive 
resource that explains this in context.

Thanks so much.
Alex