Re: linux deadline i/o elevator tuning

From: Matthew Wakeling
Subject: Re: linux deadline i/o elevator tuning
Date: ,
Msg-id: alpine.DEB.2.00.0904091531040.4053@aragorn.flymine.org
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In response to: Re: linux deadline i/o elevator tuning  (Grzegorz Jaśkiewicz)
Responses: Re: linux deadline i/o elevator tuning  (Grzegorz Jaśkiewicz)
Re: linux deadline i/o elevator tuning  ("Kevin Grittner")
List: pgsql-performance

Tree view

linux deadline i/o elevator tuning  (Mark Wong, )
 Re: linux deadline i/o elevator tuning  ("Kevin Grittner", )
  Re: linux deadline i/o elevator tuning  (Grzegorz Jaśkiewicz, )
   Re: linux deadline i/o elevator tuning  (Matthew Wakeling, )
    Re: linux deadline i/o elevator tuning  (Grzegorz Jaśkiewicz, )
     Re: linux deadline i/o elevator tuning  ("Kevin Grittner", )
      Re: linux deadline i/o elevator tuning  (Grzegorz Jaśkiewicz, )
     Re: linux deadline i/o elevator tuning  (Matthew Wakeling, )
    Re: linux deadline i/o elevator tuning  ("Kevin Grittner", )
   Re: linux deadline i/o elevator tuning  (Scott Carey, )
   Re: linux deadline i/o elevator tuning  ("Albe Laurenz *EXTERN*", )
    Re: linux deadline i/o elevator tuning  (Jeff, )
     Re: linux deadline i/o elevator tuning  ("Kevin Grittner", )
  Re: linux deadline i/o elevator tuning  (Arjen van der Meijden, )
   Re: linux deadline i/o elevator tuning  ("Kevin Grittner", )
 Re: linux deadline i/o elevator tuning  (Mark Wong, )
  Re: linux deadline i/o elevator tuning  (Mark Wong, )

On Thu, 9 Apr 2009, Grzegorz Jaśkiewicz wrote:
> acording to kernel folks, anticipatory scheduler is even better for dbs.
> Oh well, it probably means everyone has to test it on their own at the
> end of day.

But the anticipatory scheduler basically makes the huge assumption that
you have one single disc in the system that takes a long time to seek from
one place to another. This assumption fails on both RAID arrays and SSDs,
so I'd be interested to see some numbers to back that one up.

Matthew

--
 import oz.wizards.Magic;
   if (Magic.guessRight())...           -- Computer Science Lecturer


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