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

Mon Feb 22 17:02:12 UTC 2016
Scot P. Floess <sfloess at nc.rr.com>

When I was running Fedora 23 and using Xen (as the host OS), I saw 
something similar on my Dell Precision 470.  I don't recall seeing it now 
with CentOS 7, but I tend to boot that machine headless more than not...

On Mon, 22 Feb 2016, 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"
> 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?
> Regards
> Francis

Scot P. Floess             RHCT  (Certificate Number 605010084735240)
Chief Architect FlossWare  http://sourceforge.net/projects/flossware