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From: "Simon 'corecode' Schubert" <corecode at fs.ei.tum.de>
Subject: Re: RAID 1 or Hammer
Date: Wed, 14 Jan 2009 13:49:29 +0100
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References: <496b8121$0$881$415eb37d at crater_reader.dragonflybsd.org> <496b961e$0$882$415eb37d at crater_reader.dragonflybsd.org> <882FE201-9FFB-40B7-A945-DD21337DD661 at freemail.gr> <496BC215.80805 at fs.ei.tum.de> <3a7f57190901121726q69357919k52ece0b1775fdd11 at mail.gmail.com> <200901130315.n0D3FlP9038935 at apollo.backplane.com> <E663E77A-8DA0-4294-88E5-961385920B4D at opera.com> <496DA32B.8050803 at fs.ei.tum.de> <EC89B64F-B8C1-498A-8489-4258865E1CB4 at opera.com> <6D9E2264-1DAD-4B23-A03F-0636D24C363E at yberwaffe.c
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Jasse Jansson wrote:
> First of all, thanks Simon for the links, It sure was interesting reading.
> 
> On Jan 14, 2009, at 11:45 AM, Bjørn Vermo wrote:
> 
>> I have toyed with the idea that one drive in a mirrored pair ought to
>> have the addresses inverted, so sector 1 on one drive is mapped to
>> sector MAX -1 on the other.
> 
> I read it like the locality (radius) of the errors occur on the same disc,
> so I don't see the benefit from your "reversed mirror strategy".
> 
> You will also get some interesting performance problems to tackle, when
> one disc works on the inner tracks and the other one is on the outer
> tracks.

Or you get benefits for reads :)

cheers
  simon