Re: Only 3.6gb of 64gb RAM recognized by 64bit squeeze
On Tue, 2012-05-15 at 21:26 +0200, Seyyed Mohtadin Hashemi wrote:
> On Tue, May 15, 2012 at 8:51 PM, Stan Hoeppner
> <stan@hardwarefreak.com> wrote:
> On 5/15/2012 12:26 PM, Seyyed Mohtadin Hashemi wrote:
> > On Tue, May 15, 2012 at 4:30 AM, Henrique de Moraes Holschuh
> <hmh@debian.org
> >> wrote:
> >
> >> On Mon, 14 May 2012, Stan Hoeppner wrote:
> >>> On 5/13/2012 7:02 PM, Henrique de Moraes Holschuh wrote:
> >>>> On Fri, 11 May 2012, Seyyed Mohtadin Hashemi wrote:
> >>>>> On 5/10/2012 1:16 PM, Stan Hoeppner wrote:
> >>>>>> If this doesn't fix the issue, and memtest and other
> utils can see
> >> all
> >>>>>> 64GB just fine, then I'd say you're dealing with a BIOS
> bug.
> >>>>>
> >>>>> The very top of /var/log/dmesg has the kernel debug
> output about the
> >> memory
> >>>>> map. It might well tell us very quickly who is the
> culprit, if the
> >> user
> >>>>> with the problem can post it for the best working case
> and the
> >> non-working
> >>>>> [ 0.000000] e820 update range: 00000000e0000000 -
> 000000101f000000
> >>>>> (usable) ==> (reserved)
> >>>>> [ 0.000000] WARNING: BIOS bug: CPU MTRRs don't cover
> all of memory,
> >>>>> losing 61936MB of RAM.
> >>>>
> >>>> There you have it.
> >>>
> >>> I'm not surprised I was correct WRT a BIOS bug, but I am a
> little
> >>> embarrassed I didn't know and suggest this would be
> reported in dmesg.
> >>> I admit I just don't see this very often--this being the
> 1st time
> >>> actually seeing this WARNING.
> >>
> >> Well, it is the first time I've seen a BIOS screw it up so
> badly as to
> >> have someone lose 61GiB of RAM over it.
> >>
> >>>> Any of the latest versions of the longterm kernels
> (2.6.32, 3.0), or
> >>>> latest 3.2 should be able to repair MTRRs properly, but
> you have to
> >>>> compile the kernel with that option enabled. It might be
> already
> >>>> available, but not enabled by default. In that case,
> this might help
> >>>> you:
> >>>
> >>> Yep. In vanilla 3.2.6 it's selected by default in
> menuconfig, and you
> >>> can't un-select it.
> >>
> >> We _really_ need to have that enabled by default on the
> Debian kernels
> >> IMO, if we don't enable it already.
> >>
> >> --
> >> "One disk to rule them all, One disk to find them. One
> disk to bring
> >> them all and in the darkness grind them. In the Land of
> Redmond
> >> where the shadows lie." -- The Silicon Valley Tarot
> >> Henrique Holschuh
> >>
> >
> > Thank you for the tips Henrique and Stan, unfortunately i
> don't have time
> > to build/test new kernels this week because i have to finish
> my thesis. I
> > will have time next week to look at it and report back the
> results.
>
>
> In that case you could simply install the latest backport
> kernel image
> and see if that does the trick. Should be quick 'n painless.
>
> Add to /etc/apt/sources.list
> deb http://backports.debian.org/debian-backports
> squeeze-backports \
> main contrib non-free
>
> $ aptitude update
> $ aptitude -t squeeze-backports install
> linux-image-3.2.0-0.bpo.1-amd64
> $ shutdown -r now
>
> Should take less than 5 minutes.
>
> --
> Stan
>
>
> Funny you should mention that, I did actually try the exact kernel you
> mentioned yesterday - it did not go well, i got kernel panic. I didn't
> do many tests because i didn't have much time, i went back to the old
> kernel, and though i'm not happy with the situation the computer at
> least works and i can use the CPU to do calculations.
Hi Stan,
I RMA'd the MB and with the replacement I received I am able to run the
3.2 kernel and all installed RAM is usable. However, I have to use
"noapic irqpoll acpi=force" boot flags.
I did have a small problem, sometimes I would get "RAM R/W test fail" at
BIOS POST. I had done extensive memtest on the DIMMs earlier so I only
tested if the individual DIMMs could POST, only one gave the "RAM R/W
test fail". After removing the faulty DIMM + a healthy DIMM the system
works smoothly.
regards,
Mohtadin
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