Re: raid10 hard disk choice - Mailing list pgsql-performance

From Matthew Wakeling
Subject Re: raid10 hard disk choice
Date
Msg-id alpine.DEB.2.00.0905211356440.4125@aragorn.flymine.org
Whole thread Raw
In response to raid10 hard disk choice  (Linos <info@linos.es>)
Responses Re: raid10 hard disk choice  (Robert Schnabel <schnabelr@missouri.edu>)
Re: raid10 hard disk choice  (Craig James <craig_james@emolecules.com>)
Re: raid10 hard disk choice  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-performance
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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