Re: [SPAM?] Re: PG8 Tuning

From: Alvaro Herrera
Subject: Re: [SPAM?] Re: PG8 Tuning
Date: ,
Msg-id: 20050816162531.GB32695@alvh.no-ip.org
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In response to: Re: [SPAM?] Re: PG8 Tuning  (Josh Berkus)
Responses: Re: [SPAM?] Re: PG8 Tuning  ("Joshua D. Drake")
Re: PG8 Tuning  (John A Meinel)
List: pgsql-performance

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PG8 Tuning  ("Paul Johnson", )
 Re: PG8 Tuning  (Richard Huxton, )
 [SPAM?] Re: PG8 Tuning  (Steve Poe, )
  Re: [SPAM?] Re: PG8 Tuning  ("Jeffrey W. Baker", )
   Re: [SPAM?] Re: PG8 Tuning  (Jeff Trout, )
   Re: [SPAM?] Re: PG8 Tuning  (Josh Berkus, )
    Re: [SPAM?] Re: PG8 Tuning  (Alvaro Herrera <-ip.org>, )
     Re: [SPAM?] Re: PG8 Tuning  ("Joshua D. Drake", )
     Re: PG8 Tuning  (John A Meinel, )
      Re: PG8 Tuning  (Tom Lane, )
       Re: PG8 Tuning  (John A Meinel, )
        Re: PG8 Tuning  (Tom Lane, )
    Re: [SPAM?] Re: PG8 Tuning  (Michael Stone, )
     Re: PG8 Tuning  (Josh Berkus, )
  Re: [SPAM?] Re: PG8 Tuning  (Tom Arthurs, )
  Re: PG8 Tuning  (Mark Lewis, )
   Re: PG8 Tuning  (Michael Stone, )
 Re: PG8 Tuning  (Michael Stone, )
 Re: PG8 Tuning  ("Merlin Moncure", )

On Tue, Aug 16, 2005 at 09:12:31AM -0700, Josh Berkus wrote:

> However, you are absolutely correct in that it's *relative* advice, not
> absolute advice.   If, for example, you're using a $100,000 EMC SAN as your
> storage you'll probably be better off giving it everything and letting its
> controller and cache handle disk allocation etc.   On the other hand, if
> you're dealing with the 5 drives in a single Dell 6650, I've yet to encounter
> a case where a separate xlog disk did not benefit an OLTP application.

I've been asked this a couple of times and I don't know the answer: what
happens if you give XLog a single drive (unmirrored single spindle), and
that drive dies?  So the question really is, should you be giving two
disks to XLog?

--
Alvaro Herrera (<alvherre[a]alvh.no-ip.org>)
"[PostgreSQL] is a great group; in my opinion it is THE best open source
development communities in existence anywhere."                (Lamar Owen)


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