[Beowulf] Raid disk read performance issue in Linux 2.6, anyone seen this?
bogdan.costescu at iwr.uni-heidelberg.de
Tue Dec 7 05:07:09 PST 2004
On Mon, 6 Dec 2004, Craig Tierney wrote:
> an a Opteron dual 1.8 Ghz and an Itanium dual 1.4 Ghz, both running
> White Box.
I seriously doubt this. WhiteBox for Itanium ? Since when ? :-)
> The same physical computer was not used in all tests, or even for
> the same architecture.
That's messy. Different devices can behave differently with the same
driver on different architectures, due to differences in PCI
implementation, cache alignment, etc. I don't say however that this
explains the big difference that you saw between 2.4 and 2.6...
> However, since the behavior seems to cross different architectures
> with different interfaces, I don't think the problem is with an
> individual server.
Based on the description so far, I would lean towards file-system
differences. But you did not specify how you got the speed figures:
hdparm, bonnie, zcav, iozone, tiobench, something else ? The main
question being: at device level or file-system level ?
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