Return-Path: Delivered-To: 2-oracle-l@orafaq.com Received: (qmail 2530 invoked from network); 8 Aug 2007 08:19:21 -0500 Received: from freelists-180.iquest.net (HELO turing.freelists.org) (206.53.239.180) by 69.64.49.119 with SMTP; 8 Aug 2007 08:19:21 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 02012724ACF; Wed, 8 Aug 2007 09:17:03 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 24883-03; Wed, 8 Aug 2007 09:17:02 -0400 (EDT) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 68E54724774; Wed, 8 Aug 2007 09:17:02 -0400 (EDT) Received: with ECARTIS (v1.0.0; list oracle-l); Wed, 08 Aug 2007 08:34:27 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 511367217FB for ; Wed, 8 Aug 2007 08:34:27 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 12959-03 for ; Wed, 8 Aug 2007 08:34:27 -0400 (EDT) Received: from rv-out-0910.google.com (rv-out-0910.google.com [209.85.198.185]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id BB525720E55 for ; Wed, 8 Aug 2007 08:34:26 -0400 (EDT) Received: by rv-out-0910.google.com with SMTP id c27so129848rvf for ; Wed, 08 Aug 2007 05:36:44 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=Wc53Xwy0Jw5l1K+Bh6lJZu/hsiN48VTEnjoYg8nbitpIlbKRt2VaLxHbZvnFSFnIH9cLtiOYA6GZM4fl7fGDLW8tN08/lonwoGoYzzt0YWp9+idgPw20JnCl/Ek7ZJ7aFxySXen34qoxsMtMaopCBeyrHY73ahofw7hWG3Q3jvQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=Dd6Whq2ok6j6tZ2G6X0f4oVj28xzyImB8nacCKF8DhiBZlGfp0hmrwLk1+f/nUZUKSAn4/VazNKKNCx5qX4YT5vQSB0BzOVWcUSddG00M7CDlWsKYeBvJr7UJezHZw0K0iBwV6A3azt+cYjyqXR8iuIoCou0kDHwh6ribCJ95SA= Received: by 10.143.4.16 with SMTP id g16mr393743wfi.1186576603868; Wed, 08 Aug 2007 05:36:43 -0700 (PDT) Received: by 10.143.39.8 with HTTP; Wed, 8 Aug 2007 05:36:43 -0700 (PDT) Message-ID: Date: Wed, 8 Aug 2007 07:36:43 -0500 From: "Allan Nelson" To: oracle-l Subject: Re: Fencing Cache in Disk Array for Oracle In-Reply-To: <6e9345580708051243h363c75a0qa0bdc01ff5861a93@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_1918_1875088.1186576603837" References: <6e9345580708051243h363c75a0qa0bdc01ff5861a93@mail.gmail.com> X-archive-position: 411 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-to: oracle-l-bounce@freelists.org X-original-sender: anelson77388@gmail.com Precedence: normal Reply-to: anelson77388@gmail.com List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: oracle-l X-List-ID: oracle-l List-subscribe: List-owner: List-post: List-archive: X-list: oracle-l X-Virus-Scanned: Debian amavisd-new at localhost.localdomain ------=_Part_1918_1875088.1186576603837 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline The cache he is talking about is in the array and hence is not available to the SGA. I fear that you are in for some iteration. The amount of usable cache memory depends on the unique I/O signature of your database. With this particular array, and assuming you have 2Gb fibre you should expect reads and writes always down in single digit ms area. Tune with your choic= e of tool until you are as close to this as possible. Allan On 8/5/07, LS Cheng wrote: > > one of opinions here: > > http://blogs.smugmug.com/don/2007/04/27/the-perfect-db-storage-array/ > > MySql focused but applies to any database vendor > > Thanks > > -- > LSC > > > > On 8/4/07, Binh Pham wrote: > > > > I'm currently working on a project that involves a new HP XP12000 > > Disk Array. The newly acquired array would have 240G of cache on the a= rray > > that allows data to be cached between the physical disks and the server= s. > > This model allows an amount of cache to be dedicated (fenced) to a spec= ific > > host, in this case, the production server therefore other non-productio= n > > related activities can pollute the production cache. The rest of the c= ache > > can be shared among the rest of the non-production servers. > > > > My question is that how much cache should be allocated to ensure top > > performance in terms of IO for the production server? I'm not comforta= ble > > with throwing out a number and say that it is good. What I'm looking f= or is > > some researchable facts that back up the number (for example, something= that > > I can mine from statspacks or similar that can be used to determine thi= s > > number). > > > > Thanks for any input. > > > > Binh Pham > > > > > > ------------------------------ > > Messenger Caf=E9 =97 open for fun 24/7. Hot games, cool activities serv= ed > > daily. Visit now. > > > > > > ------=_Part_1918_1875088.1186576603837 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline The cache he is talking about is in the array and hence is not available to= the SGA.  I fear that you are in for some iteration.  The amount= of usable cache memory depends on the unique I/O signature of your databas= e.  With this particular array, and assuming you have 2Gb fibre you sh= ould expect reads and writes always down in single digit ms area.  Tun= e with your choice of tool until you are as close to this as possible.

Allan

On 8/5/07, LS Cheng <exriscer@gmail.com> wrote:
one of opinions here:
 
 
MySql focused but applies to any database vendor
 
Thanks
 
--
LSC


 
On 8/4/07, Binh Pham <
I'm currently working on a project that involves a new HP XP12= 000 Disk Array.  The newly acquired array would have 240G of cache on = the array that allows data to be cached between the physical disks and the = servers.  This model allows an amount of cache to be dedicated (fenced= ) to a specific host, in this case, the production server therefore other n= on-production related activities can pollute the production cache.  Th= e rest of the cache can be shared among the rest of the non-production serv= ers.
 
My question is that how much cache should be allocated to ens= ure top performance in terms of IO for the production server?  I'm= not comfortable with throwing out a number and say that it is good.  = What I'm looking for is some researchable facts that back up the number= (for example, something that I can mine from statspacks or similar th= at can be used to determine this number).
 
Thanks for any input.
 
Binh Pham
=

Messenger Caf=E9 =97 open for fun 24/7. Hot games, cool activities served d= aily. V= isit now.


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