Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id ADE7C6325E9 for ; Sat, 11 Apr 2009 15:44:36 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 28542-07 for ; Sat, 11 Apr 2009 15:44:35 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from rv-out-0506.google.com (rv-out-0506.google.com [209.85.198.231]) by mail.postgresql.org (Postfix) with ESMTP id 03701632439 for ; Sat, 11 Apr 2009 15:44:34 -0300 (ADT) Received: by rv-out-0506.google.com with SMTP id f6so1271882rvb.3 for ; Sat, 11 Apr 2009 11:44:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=u9a5/j1lCEJ1fh9+799vtFTZAAn2hTePWL3GqS9OZnw=; b=L1QddX8GMMZi4pyE3avjjoZ5ecIoW/5W0wAwUMzfFQEsPgCNTK87T652L2xzinvKE2 LiGXZvMkpo7zocLCRQTgtd6TVIhqNYEyB8lJXku46Oj4Vl7nsQ/Fcl1IKZJc1VEDpE02 UlX8w8geaAoDyRPzlNJZ38bJF8zzZrJvHOQY4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=oPY/x9hag6yUI3sI+4ZJmaNuy7pYG70ZYcE8IzXxp20VcSI9Uvd3O/p+miKAwzC+VI YdR8tvnONknqb+GfW33LnMmmPxtUrZOk15H6dsCbOKKYGF/IdrRM+la2CIyN2PitC1YU 6YN39vcFqw+VRErher7K9bnz/NSE79KmBzkXU= MIME-Version: 1.0 Received: by 10.141.62.9 with SMTP id p9mr2002762rvk.86.1239475473601; Sat, 11 Apr 2009 11:44:33 -0700 (PDT) In-Reply-To: References: Date: Sat, 11 Apr 2009 11:44:33 -0700 Message-ID: <70c01d1d0904111144m50c569bbh7dc32f2bce36195e@mail.gmail.com> Subject: Re: Using IOZone to simulate DB access patterns From: Mark Wong To: Greg Smith Cc: Scott Carey , Josh Berkus , henk de wit , "jesper@krogh.cc" , "pgsql-performance@postgresql.org" , Selena Deckelmann , Gabrielle Roth Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200904/215 X-Sequence-Number: 33582 On Fri, Apr 10, 2009 at 11:01 AM, Greg Smith wrote: > On Fri, 10 Apr 2009, Scott Carey wrote: > >> FIO with profiles such as the below samples are easy to set up > > There are some more sample FIO profiles with results from various > filesystems at > http://wiki.postgresql.org/wiki/HP_ProLiant_DL380_G5_Tuning_Guide There's a couple of potential flaws I'm trying to characterize this weekend. I'm having second thoughts about how I did the sequential read and write profiles. Using multiple processes doesn't let it really do sequential i/o. I've done one comparison so far resulting in about 50% more throughput using just one process to do sequential writes. I just want to make sure there shouldn't be any concern for being processor bound on one core. The other flaw is having a minimum run time. The max of 1 hour seems to be good to establishing steady system utilization, but letting some tests finish in less than 15 minutes doesn't provide "good" data. "Good" meaning looking at the time series of data and feeling confident it's a reliable result. I think I'm describing that correctly... Regards, Mark