Re: Tuning Linux for high-speed disk subsystems

[Craig I. Hagan]

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> After some testing at Compaq's lab in Oslo, I've come to the conclusion
> that Linux cannot scale higher than about 30-40MB/sec in or out of a
> hardware or software RAID-0 set with several stripe/chunk sizes tried out.
> The set is based on 5 18GB 10k disks running SCSI-3 (160MBps) alone on a
> 32bit/33MHz PCI bus.

this isn't quite true. use either the RH kernel, the -ac series, or the
attached patch (for 2.4.15-pre4). Then set /proc/sys/vm/max-readahead to 511 or
1023 (power of 2 minus 1)

this should allow you to generate large enough io's for streaming reads to do
what you are looking for.
	
-- craig

-------------------------------------------------------------------------------
Craig I. Hagan     "It's a small world, but I wouldn't want to back it up"
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