[CentOS-virt] Video resolution for CentOS guest

Digimer
Tue, 24 Feb 2015 04:53:40 -0000

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On 23/02/15 11:11 PM, Robert Nichols wrote:
> Would someone please point me to some reasonably current
> instructions for getting greater than 1024x768 video resolution for
> a CentOS 6 guest on a CentOS 6 KVM/qemu host?  When I search online
> I find stuff from 2009 and 2010 saying, "For details see ...,"
and
> linking to a URL that no longer exists, or pages that say, "You
> need to switch from VNC to Spice," and giving a long list of
> out-of-date instructions for doing so.  (With virt-manager it takes
> 2 clicks to do that.  Of course it doesn't help -- still maxes out
> at 1024x768.)
>
> I've found that I can just append "vga=0x380" to the kernel
> command line and see Plymouth come up with the full graphical boot
> screen in the correct 1440x900 resolution, but as soon as gdm
> starts up, the display scrambles.  I find suggestions to generate
> an xorg.conf file, but no mention of what to put in it.  I can run
> "Xorg -configure", but the resulting file contains nothing about
> video modes, so it's not apparent what needs to be added.
>
> I find it particularly annoying that a Windows 7 guest can set any
> resolution I want up to 2560x1600, but a Linux guest can't go
> higher than 1024x768.

I played with this and found that, in fact, I had to switch the spice
/ qxl. With that change, I had no trouble pushing EL6 to much higher
resolutions.

- --
Digimer
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