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

Alvin Starr alvin at netvel.net
Mon Feb 22 18:11:27 UTC 2016


I get the same effect of screen blank on memory scrub.

Just as a test try turning off the memory scrub in the xen boot options.

I wonder if xen overwrites the video-ram memory as its cleaning up.

On 02/22/2016 01:06 PM, Scot P. Floess wrote:
> Francis,
>
> I just rebooted my Precision 470 and watched...nothing :(
>
> I see the boot menu, and then everything goes blank - as in just a 
> blinking cursor until I get the login prompt.
>
> No idea what it's doing - but I don't even see the scrubbing free 
> memory output...
>
> On Mon, 22 Feb 2016, Francis Greaves wrote:
>
>> Yes I usually work headless, but I have been setting it up from new, 
>> so need to see what is going on.
>> Regards
>> Francis
>>
>>
>> _________________________________________________________________________________________________________________________________________________________ 
>>
>> From: "Scot P. Floess" <sfloess at nc.rr.com>
>> To: "Francis Greaves" <francis at choughs.net>
>> Cc: "centos-virt" <centos-virt at centos.org>
>> Sent: Monday, 22 February, 2016 17:02:12
>> Subject: Re: [CentOS-virt] Garbled screen after RAM Scrub on boot
>>
>> 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_DEFAULT=saved
>> > GRUB_DISABLE_SUBMENU=true
>> > 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_GFXPAYLOAD_LINUX=keep
>> > 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
>>                             http://flossware.sourceforge.net
>>  https://github.com/organizations/FlossWare
>>
>>
>
> Scot P. Floess             RHCT  (Certificate Number 605010084735240)
> Chief Architect FlossWare http://sourceforge.net/projects/flossware
>                            http://flossware.sourceforge.net
> https://github.com/organizations/FlossWare
>
>
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> CentOS-virt at centos.org
> https://lists.centos.org/mailman/listinfo/centos-virt


-- 
Alvin Starr                   ||   voice: (905)513-7688
Netvel Inc.                   ||   Cell:  (416)806-0133
alvin at netvel.net              ||

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