M620 works with one cpu, not with two

Question

Hi,

I have m1000e chassis with 4 M620 blades. 2 were running for a year, I have added two more now.

Those two newly added I equipped with 2x E5 2680 v2 + 4 x udimm 8GB.

They are stuck on "Configuring memory..." both, the same.

I thought maybe memory issue/incompatibility, I replaced RAM with ones already working in previous 2 servers -> result same

Then I removed cpus and I have installed just one CPU and "new" memory, but just one in A1 slot -> server works

I was happy.

I did full update of firmware, BIOS 2.9.0, Idrac 2.65.65.65 and so on.

I thought my problems are gone.

I installed again two CPUs (E5 2680 v2) + memory A1, B1 -> again "Configuring memory..."

Then I thought, maybe second CPU issue, I put second CPU in slot 1 -> it works, so both CPUs are ok if working in slot 1, alone, in single cpu configuration.

Then I entered again both CPUs and memory A1, B1 -> again "Configuring memory..."

So the conclusion is server works when only one CPU installed, when two installed it doesn't. Both CPUs work well in a single CPU configuration, so it shouldn't be a CPU failure.

I would say mainboard issue or CPU 2 socket, but why two server blades behave exactly same?

Any ideas?

Two blades with same mainboard/cpu 2 socket failure?

CMC firmware 6.21 - latest

Same CPUs 2 x E5 2680v2 I have entered to one of my "old" M620 and they work well, memory same as inserted to new blades installed in other blade also work well, so compatibility is not an issue I hope.

bbroniewski · Accepted Answer

So, the solution is to install other RAM dimms which are supported officially. It is weird that one processor is fine with the same memory and two not, but this is a reality. Both servers works just fine with RDIMM's 2Rx4.

The memory which doesn't work with two 2680 v2 processors works well with older processors, but you don't have guarantuee. So my advise, use officialy supported ones or test and replace with other memory modules if you see same issue.

bbroniewski · Answer

Memories are of the same type and are working fine in the same setup in other blade. Just not with the same cpus.

I removed mezzanine card, result same. Removed HDD backplane, same.

iDrac logs says about issue with HDD, but it only came when system noramally boots, when I have this issue with configuring memory screen it is not reaching that moment to check HDD issue (no OS yet, so nothing to start).

CMC logs is not telling anything about it.

I only think maybe E5 2680 v2 + that exact RAM are not compatibile. I will check it on older blade now.

Because same memory in the same setup in other blade works and same CPUs in other blade also works, but I don't have anyware same CPUs + same RAM. Maybe there is some incompatibility correlation between that model of CPU and that model of RAM.

DELL-Shine K · Answer

Can you check logs in iDRAC and CMC to see whether it have any information related to booting of the server?

Can you remove mezzanine cards (if any) from the server and check. Is all memory you are installing on the server are same type?

bbroniewski · Answer

I just moved same memory to the blade with 2 x E5 2680 v2 CPUs and it hangs the same way. So it looks like CPU no compatibile with those memories, but one CPU with this memory is fine, just not two...

How it may be, that one is ok, with the same memory, but two not... unbelievable

DellUserMichael · Answer

Same issue for me. I literally have 4 T420's. I owned 1 and bought 3 off Ebay and or cases and new motherboards

In all cases but 1, the used motherboards and or full machines came with only 1 CPU. And no matter what I do if i add a second, perfect matching and just re-use the memory it came with.. nope

Nadda... it gives me a voltage error and its like umm.. say what lol

bbroniewski · Answer

I have ordered a samsung load reduced RAM now, officialy supported by M620. I will message you here about the result. I hope there will no issue that time.

PowerEdge Hardware General

M620 works with one cpu, not with two

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