Re: raind-1 resync speed slow down to 50% by the time it finishes

["Keld Jørn Simonsen" <keld@dkuug.dk>]

On Fri, Jul 31, 2009 at 07:54:55PM +0200, Keld Jørn Simonsen wrote:
> On Thu, Jul 30, 2009 at 01:11:20PM -0700, David Rees wrote:
> > 2009/7/30 Keld Jørn Simonsen <keld@dkuug.dk>:
> > > I think raid10,f2 only degrades 10-20 % while raid1 can degrade as much
> > > as 50 %. For writing it is about the same, given that you use a file
> > > system on top of the raid.
> > 
> 
> > Random/small reads far: Up to 100% faster
> 
> Actually a bit more, due to that far only uses the fastest half of the
> disks. One test shows 132 % faster, which is consistent with theory.
> 
> > Random/small reads near: Up to 100% faster
> 
> One test shows 156 % faster.

I meant 56 % faster.

So one test (done by myself) shows far to be 132 % faster than single
disk, and near to be 56 % faster. Given the behaviour of near and far I
believe the tests to be representative of the near/far performance for
random reading.

Best regards
keld
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