[Beowulf] Re: mysterious slow disk

[Erwan]

David Mathog wrote:
> I don't think I'm going to solve this one :-(
>   
Here come some ideas.

If you invert a disk from a good node and a bad node, does the good node 
becomes bad ?
If yes, the disk is the problem, not the host.
If no, the host is the problem.
This test will help us searching in the right direction.

Maybe the pci latency isn't the same, could you diff a lspci -vvv 
between a good and a bad host ?
Could you also diff the dmidecode of a good and a bad host ? Maybe we 
missed something.

Could you provide a "smartctl -A /dev/<disk>" output for a good and a 
bad disk ?
Maybe their proprietary tools could diagnose something we can't see 
directly:
http://websupport.wdc.com/rd.asp?p=sw30&t=122&lang=fr&s=http://support.wdc.com/download/dlg/Diag504cCD.iso

I'm out of ideas for the moment ;o)
Erwan,

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