Re: raid10 hard disk choice

From: Matthew Wakeling
Subject: Re: raid10 hard disk choice
Date: ,
Msg-id: alpine.DEB.2.00.0905211356440.4125@aragorn.flymine.org
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In response to: raid10 hard disk choice  (Linos)
Responses: Re: raid10 hard disk choice  (Robert Schnabel)
Re: raid10 hard disk choice  (Craig James)
Re: raid10 hard disk choice  (Robert Haas)
List: pgsql-performance

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raid10 hard disk choice  (Linos, )
 Re: raid10 hard disk choice  (Matthew Wakeling, )
  Re: raid10 hard disk choice  (Robert Schnabel, )
   Re: raid10 hard disk choice  (Scott Marlowe, )
   Re: raid10 hard disk choice  (Greg Smith, )
    Re: raid10 hard disk choice  (Robert Schnabel, )
     Re: raid10 hard disk choice  (Greg Smith, )
      Re: raid10 hard disk choice  (Scott Marlowe, )
       Re: raid10 hard disk choice  (Greg Smith, )
        Re: raid10 hard disk choice  (Robert Schnabel, )
  Re: raid10 hard disk choice  (Craig James, )
  Re: raid10 hard disk choice  (Robert Haas, )
   Re: raid10 hard disk choice  (Scott Marlowe, )
    Re: raid10 hard disk choice  (Scott Carey, )
    Re: raid10 hard disk choice  (Robert Haas, )
     Re: raid10 hard disk choice  (Scott Carey, )
    Re: raid10 hard disk choice  (Greg Smith, )
 Re: raid10 hard disk choice  (Merlin Moncure, )
  Re: raid10 hard disk choice  ("Joshua D. Drake", )
 Re: raid10 hard disk choice  (Linos, )

On Thu, 21 May 2009, Linos wrote:
>     i have to buy a new server and in the budget i have (small) i have to
> select one of this two options:
>
> -4 sas 146gb 15k rpm raid10.
> -8 sas 146gb 10k rpm raid10.

It depends what you are doing. I think in most situations, the second
option is better, but there may be a few situations where the reverse is
true.

Basically, the first option will only be faster if you are doing lots of
seeking (small requests) in a single thread. As soon as you go
multi-threaded or are looking at sequential scans, you're better off with
more discs.

Matthew

--
 Experience is what allows you to recognise a mistake the second time you
 make it.


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