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Re: Scsipi guru needed...
On Sun, 30 Nov 2008, Anders Magnusson wrote:
I have been trying to find out why the performance of the ciss controller
(Compaq raid) in
DL38x is really bad, but as I don't understand anything about the scsipi
layer (are there any docs?) I must ask around. All this is really strange.
Writing data to the raw sd device (bs=64k) gets just over 7MB/s, which is
Some debugging showed that:
- A write transfer (from given to the ctlr to interrupt) takes 8ms. Ok, no
write cache on the ctlr maybe?
Does your controller have a battery backup? I've found that without the
battery backup, the controller does not use any write cache and write
speeds are significantly reduced.
Michael L. Hitch mhitch%montana.edu@localhost
Information Technology Center
Montana State University Bozeman, MT USA
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