E1422 CPU2 machine check error. Power cycle AC.

Hanne Munkholm hanne at binf.ku.dk
Mon Mar 21 09:56:17 CDT 2011


I have some new R815 servers with 4 x 12core AMD opteron 6174
and 256 / 128 GB RAM.

When I enable the "DMA Virtualization" in BIOS (under Processor
Settings), I get this error message in the display:

"E1422 CPU2 machine check error. Power cycle AC."

This happenes both with BIOS 1.3.1 and 1.4.1.

I first saw it Friday and I went straight up and opened a
support case with Dell. The servers are not in production yet
and I want it solved before they are.

The Dell engineer was very helpful and suggested some things. I
had just upgraded the BIOS to 1.4.1 and thought that this might
have caused it, so he checked that all my other firmware was up
to date etc. Which it was. He also suggested reseating all the
components, clearing the log, and if it did not go away,
downgrading the BIOS.

I adopted another strategy since I had 3 more servers to play
with. I upgraded BIOS on one more - no error. Then I enabled DMA
Virtualization on one more, with "old" BIOS 1.3.1 and the error
was there right away.

So I disabled it again and cleared the log and it did not come
back. (I have not cleared the log of the first server since I
might not be done with it).

I still have the case open with Dell, the engineer promised to
ask their second level support so I guess it is not a normal
everyday issue.

My questions to this list is:

1) What is DMA virtualization in BIOS exactly supposed to do? It
did not make the 
"[    0.000000] Your BIOS doesn't leave a aperture memory hole
[    0.000000] Please enable the IOMMU option in the BIOS setup
[    0.000000] This costs you 64 MB of RAM"

message in my dmesg log go away, which is why I enabled it in
the first place.

2) Has anyone seen this before?

3) Does anyone have a clue why this happens? What does "E1422
CPU machine Chk" mean anyway?

Thanks in advance for any clue, or pointers to documentaion that
would make this clearer.

Med venlig hilsen / Best regards
Hanne Munkholm                      Email: hanne at binf.ku.dk
Systemadministrator                 Tlf: +45 35 32 13 49

Københavns Biocenter, Biologisk Institut
Ole Maaløes Vej 5, 2200 København N

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