[CentOS-virt] Re: Garbled screen after RAM Scrub on boot

Tue Feb 23 18:53:43 UTC 2016
Yamaban <foerster at lisas.de>

On Tue, 23 Feb 2016 14:40, Francis Greaves wrote:
> Dear George,
> Thanks for the input and ideas.
> Unfortunately bootscrub=false dos not work, not does setting nothing for vga, still get the 'Little white squares'!
> I am asking the xen-users as you suggest
> Regards, Francis
> From: "George Dunlap" 
> To: "Francis Greaves" , "centos-virt"
> Sent: Tuesday, 23 February, 2016 09:31:40
> Subject: Re: [CentOS-virt] Garbled screen after RAM Scrub on boot
> On Mon, Feb 22, 2016 at 4:18 PM, Francis Greaves wrote:
>> Dear All
>> I am using Centos 7 with Xen 4.6 on a Dell Poweredge T430
>> When the machine boots, after the 'Scrubbing Free RAM' message, I get a
>> screen filled with little white squares until the login prompt, so I cannot
>> see what is happening as the machine boots. Also there is nothing on the
>> screen when I reboot.
>> My /etc/default/grub is
>> GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
>> GRUB_CMDLINE_LINUX="crashkernel=auto rhgb intremap=no_x2apic_optout"
If you no not NEED a gfx boot at bare metal, remove the "rhgb" string,
this switches grub from a "full graphic" mode to a "hires textmode",
AFAICS, this also influences all grub instances in the whole XEN
infrastructure, so it could be a influence.

>> GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=13312M,max:14336M dom0_max_vcpus=6 dom0_vcpus_pin"
>> GRUB_GFXMODE=1024x768
>> GRUB_CMDLINE_LINUX_XEN_REPLACE_DEFAULT="console=hvc0 earlyprintk=xen
>> nomodeset"
>> I have tried setting (for a 1024x768 resolution) vga=792 in the
>> GRUB_CMDLINE_LINUX and commenting out GRUB_GFXMODE and
>> GRUB_GFXPAYLOAD_LINUX, but this makes no difference
>> What am I doing wrong?

  - Yamaban.