Mr. James W. Laferriere wrote:

    Hello Andrew ,

On Tue, 17 Jul 2007, Andrew Burgess wrote:

quoted

quoted

    The 'MCE's have been ongoing for sometime .  I have replaced 
every item
in the system except the chassis & scsi backplane & power 
supply(750Watts) .
    Everything .  MB,cpu,memory,scsi controllers, ...
    These MCE's only happen when I am trying to build or bonnie++ 
test the
md3 .  It consists of (now 7+1spare) 146GB drives in the SuperMicro
SYS-6035B-8B's backplane attached to a LSI22320 .

Probably every old timer has a story about chasing a hardware problem
where changing the power supply finally fixed it. I keep spares now.

If an MCE (which means bad cpu) doesn't go away after changing the cpu
it would either have to be temperature, power or a bug in the MCE code.
What else could it be?

    Thank you for the idea of 'changing out the PS' .  So I did it a 
bit differant .  I removed the system PS from the raid backplane & 
dropped in a known good ps of proper wattage & re-tested .  But left 
the systems ps attached to only the MB & fans .
    It doesn't appear to be power load related .  I tried rebuilding 
my 7 disk raid6 array & I got the same thing ,  MCE .
    Now the raid backplane is still in the air stream in front of the 
cpu's and memory slots .  So it could be a marginal cpu or memory stick .

    But here's the clincher ,  when I don't use the two drives in from 
of the PS & cpu & memory slots .  The array completes it's resync .  
So I'm back to testing memory (again) ,  If that passes then I'll try 
the new cpu(s) route .

It does sound like a cooling problem, which does not have to imply the 
overheated parts are bad, although that may be true. Could be the total 
number of i/o in flight, etc. Have you tried dropping two other drives? 
Can you put in a bit more fan? Read the system board and CPU temps with 
the "sensors" package?

-- 
bill davidsen [off-list ref]
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979