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: Having both dbwr_io_slaves and disk_asynch_io set

Re: Having both dbwr_io_slaves and disk_asynch_io set

From: Jared Still <jkstill_at_gmail.com>
Date: Wed, 8 Dec 2004 10:37:23 -0800
Message-ID: <bf463804120810372ef1956c@mail.gmail.com>


Ah, good question.

I have access to Solaris, but not the correct version.

On Wed, 8 Dec 2004 12:26:21 -0500, Richard Ji <richard.c.ji_at_gmail.com> wrote:
> Jared,
>
> As far as I understand it. On Solaris 8 and onward, by default
> Asynch IO is turned on and Oracle will use it by issue a KAIO. If it's
> raw device or Veritas quick IO, the KAIO will succeed. Otherwise
> KAIO will fail and an AIO that's simulated by LWP doing pwrite() will
> happen. That's why there are 258 LWP under the DBWR process.
>
> Now, I can turn Asynch IO off and use Oracle's dbwr slaves to
> simulate that as well. But as far as I know, one would only want
> to do that on a platform that doesn't support AIO. In either case,
> you chose one way or the other. But on this DB that I saw, both
> are set. So I am wondering which one will it use? I don't have
> enough permission on the system to truss the process or anything.
> So I wonder if anyone has seen it before and the implication of
> having both set.
>
> Best regards
>
> Richard Ji
>
>

-- 
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist
--
http://www.freelists.org/webpage/oracle-l
Received on Wed Dec 08 2004 - 12:45:29 CST

Original text of this message

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