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From: Eric Anderson <anderson@centtech.com>
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To: Ivan Voras <ivoras@fer.hr>
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Cc: freebsd-geom@freebsd.org
Subject: Re: gstripe performance scaling with many disks
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On 12/28/06 12:27, Ivan Voras wrote:
> Ivan Voras wrote:
> 
>> I'll take a shot at this: Since maximum kernel reads are still limited
>> to 128 KB/s, by adding more drives you're making individual requests
>> shorter. I.e. with one drive, it gets 128 KB requests, with two, each
>> gets 64 KB, with 16, each gets 8 KB. So network & kernel latency becomes
>> visible.
> 
> Btw. if I'm right, you should be able to observe this with gstat and/or
> iostat. If you don't see it, then it's possible I'm wrong :)

Maybe this should be tried with md* devices just to remove the network 
component from this mix.

Eric


-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
An undefined problem has an infinite number of solutions.
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