Dell PE4600 RAID5 server failing
hakmi at rogers.com
Wed Nov 14 10:37:39 PST 2007
> Derek Ragona wrote:
> > At 09:00 AM 11/14/2007, Barnaby Scott wrote:
> >> I suspect I already know the answer to this, which is that the
> >> trouble I am having is nothing to do with the OS at all,
> but I have
> >> to ask, because I am otherwise up against a total brick wall!
> >> I bought a second-hand Dell Poweredge 4600 and installed
> FreeBSD 6.2
> >> earlier this year. I had it set up with RAID5 using its PERC3/DC
> >> controller, with 7 x 73GB disks (+ 1 hot spare). So far so
> good, and
> >> it worked faultlessly as a Samba server for several months.
> >> At the beginning of October, it went down, reporting a mismatch
> >> between the configuration on the NVRAM and the disks. With
> help from
> >> Dell support, I managed to recreate the RAID array and it worked
> >> again for a month.
> >> In early November it happened again, and has kept
> happening since. At
> >> one point it appeared that the backplane was faulty, so I replaced
> >> that, but I cannot keep the server up for more than a day or so
> >> without this 'mismatch' poblem.
> >> What about diagnostics on the hardware you may ask? I have run all
> >> the diagnostic tools that Dell can supply - several times
> - and the
> >> server declares itself to be totally fault-free.
> >> My specific questions therefore:
> >> Is there any way at all that FreeBSD could be invloved with this
> >> problem? (I did notice for example that the Dell PERC3/DC
> >> was not in the list of supported hardware - but then
> again, why did
> >> it work for several months?)
> >> Can I use FreeBSD to tell me anything about the fault that Dell's
> >> diagnostic tools haven't found?
> >> (I do hope someone might be able to help - Dell are trying
> to get me
> >> to switch to a 'supported' OS!)
> >> Thanks
> >> Barnaby Scott
> > It doesn't sound like any OS issue as you set up the RAID
> outside the
> > OS. It may be a bad drive or drive(s). Most RAID drives have RAID
> > information written to the drives, and if this becomes
> unreadable you
> > will have RAID faults.
> > Another likely culprit is heat. Overheating drives often
> fail. Are
> > you sure the temperatures in the drive enclosure is OK?
> > If you can, run diagnostics on the drives, this usually requires
> > running these with the drives taken out of the RAID array though.
> > -Derek
> Thanks for replying - as I said, this is a long shot trying
> to see if there is any OS involvement.
> The drives are fine - I have used two different tools to
> analyse them while the computer is booted from a live CD and
> the RAID configuration cleared on the controller. Besides,
> you would expect one drive to fail at a time, and if this
> happened, the hot spare would surely be pressed into service.
> Nothing like this has happened though - the controller is
> reporting several drives (not always the same ones) failed
> simultaneously, but when the array is re-created from the
> disks, everything works fine. Problem is, it goes down again
> a day or so later.
> As for heat, there is nothing being reported there and the
> fans that cool that area are working.
> Any other ideas gratefully received!
> Barnaby Scott
This is very unlikely to be OS related. But here are few pointers:
1) Check the make/model of the drives. Certain types of make/model SCSI drives had a glitch in them a while ago with a certain firmware that they'd disconnect from a RAID. I had a personal experience with these ones (Seagate U320).
2) What did happen in October? Anything hardware, software, power wise has occurred ?
3) NVRAM and Disk mismatch, I'd say check the controller, backup battery present but weak ?
4) Unlikely to be the source, but run a test on your physical RAM using MEMTEST86+ and check the power supply is sufficient and working properly.
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