Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Re: OT: high WIO on Linux

Re: OT: high WIO on Linux

From: Christo Kutrovsky <kutrovsky.oracle_at_gmail.com>
Date: Wed, 15 Mar 2006 15:47:23 -0500
Message-ID: <52a152eb0603151247kd48bc8fg6dd3a89becdf053f@mail.gmail.com>


Yes i've noticed that 2.4 is not "optimal" to be polite.

The SAN we have does not have average IO size. I know for sure 2.6 is way better on large IOs, I just dont know wether I can fully thrust iostat. What's your observeation with RH4 and the 2.6 kernel ?

On 3/15/06, Kevin Closson <kevinc_at_polyserve.com> wrote:
> >>>I've always wondered that. How can you determine that? Is
> >>>the iostat average IO size per device any good for this ?
> >>>
> >>>Sometimes even if it does chew it up in 64k requests, I find
> >>>it's better to have it large, so that you can queue up a
> >>>large number of IOs in a serial read process.
> >>>
>
> iostat -x will help you resolve that. Some of the
> many SANs we have inhouse here also report out what the
> average transfer size is...and if I'm doing, say,
> a CCF or LWS, I should be hitting the array at 1MB, but
> if I'm on something like RH3 (puke all over please so I don't
> have to) it'll be more like 32KB or 64KB "chunklets"...
>
> The 2.6 kernel is not so messed up this way. You are right too,
> that even if it gets chopped down into smaller requests, it is
> still better to have Oracle through out the larger requests.
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

--
Christo Kutrovsky
Senior Database/System Administrator
The Pythian Group
--
http://www.freelists.org/webpage/oracle-l
Received on Wed Mar 15 2006 - 14:47:23 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US