decoding MCE Logs? Possible hardware issue?

[Derek Atkins]

Jarod,

On Tue, September 28, 2010 10:10 pm, Jarod Wilson wrote:
> On Tue, Sep 28, 2010 at 10:02 PM, Derek Atkins <derek-CrUh67yIh4IAvxtiuMwx3w at public.gmane.org> wrote:
>> Ok,
>>
>> On Tue, September 28, 2010 9:47 pm, Jarod Wilson wrote:
>>> On Tue, Sep 28, 2010 at 9:48 AM, Derek Atkins <warlord-3s7WtUTddSA at public.gmane.org> wrote:
>>>> I noticed the following in my mcelog, and I was hoping someone could
>>>> help be decode this.  My google fu has not let me to an answer.
>>>>
>>>> I'm running a Supermicro H8DA3-2 with two Quad-Core AMD Opteron(tm)
>>>> Processor 2378 and 16GB of RAM (8 sticks of ACTICA DDR2 667 2GB ECC
>>>> REG)
>>>> purchased with the machine in Jan, 2009.
>>>>
>>>> Is this a memory issue?
>>>
>>> At first glance, it looks to be a bad cpu l3 cache, but hard to say for
>>> sure...
[snip]
>> tail -6 /var/log/mcelog  | mcelog --k8 --ascii
>> MCE 0
>> HARDWARE ERROR. This is *NOT* a software problem!
>> Please contact your hardware vendor
>> MISC c008000001000000 ADDR 234909fc0
>> STATUS 9c524484001d011b MCGSTATUS 0
>> HARDWARE ERROR. This is *NOT* a software problem!
>> Please contact your hardware vendor
>> CPU 0 0 data cache MISC c008000001000000 ADDR 234909fc0
>>  Data cache ECC error (syndrome a4)
>>       bit34 = err cpu2
>>       bit42 = L3 subcache in error bit 0
>>       bit46 = corrected ecc error
>>       bit59 = misc error valid
>>  memory/cache error 'generic read mem transaction, generic transaction,
>> level generic'
>> STATUS 9c524484001d011b MCGSTATUS 0
>> (Fields were incomplete)
>>
>> So what does this mean?
>
> Well, mcelog seems to think you have a bad CPU, but I'd have to talk
> to some of the hardware folks at work to get a better idea exactly
> what's up. Seems possible its just an ecc memory error too though, and
> one that was corrected. Do you have any edac modules loaded? Not sure
> if that box needs edac_amd64 or something else, and/or when exactly it
> was that edac_amd64 finally got merged upstream (and therefore into
> the Fedora kernels). Yeah, lemme (try to remember to) poke some folks
> who actually work on this code and know the hardware better
> tomorrow...

Thanks.  It *is* ECC memory.  I'd much rather replace my 2yo ECC RAM than
replace my CPU.  In either case it's annoying.

I temporarily downgraded from 2.6.34.6-54 to 2.6.27.41-170.2.117 in order
to keep my VMs from dying and this seems to be helping.  Running 2.6.34
I'd have periodic cases where VMs would spin, md_raid would spin, and the
network would drop to all my VMs, and sometimes the VMs would report
ATA/SCSI disk errors.  I didn't have any of those issues prior to
upgrading, and haven't had them since rebooting into the older kernel.

But I suspect there's still really a hardware problem somewhere.  :(

> Jarod Wilson
> jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org

-derek