Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 8D2BC632A8C for ; Sun, 22 Mar 2009 12:29:39 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 94719-09 for ; Sun, 22 Mar 2009 12:29:37 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.177]) by mail.postgresql.org (Postfix) with ESMTP id C50D0632468 for ; Sun, 22 Mar 2009 12:29:37 -0300 (ADT) Received: by wa-out-1112.google.com with SMTP id v33so1532863wah.19 for ; Sun, 22 Mar 2009 08:29:36 -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=wNq2hD3GjZ/xA/bN4pupEwhtSdRQD+CuuOU+gMLn+/o=; b=ANrEmQbJ/pJUFEz/Z/2RWvoRcbWzwM0C0BgrKKrexdGYxMl5kKBObenDjUCRwLLMKx QRrBfdNbbRZOnLNzWYrVxVEv+5+L53lgATAffl1mc/FPxCmfIi+MYjDluZ1YhfTZRbWp HhUizYLObtGDbY/Ilnr5akEQnT1ptW95g2HvI= 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=Nl/TrkutLvuIjOuiaFZ5Zd8gxR2zy5GVtpkrsWy2AiQrBoi8iIw4nuGkdBl/Kkyv+M /BtO6leOvra9JjVC0NP70jJnXUZ8RPgXmdusVzdJT1ti8WQ0oeWiEB6K29uJWfiavUfs YFlJW+B+voCwZRXCmbO7Wl555QkOmEPMp3KII= MIME-Version: 1.0 Received: by 10.114.170.1 with SMTP id s1mr4107952wae.57.1237735776024; Sun, 22 Mar 2009 08:29:36 -0700 (PDT) In-Reply-To: References: Date: Sun, 22 Mar 2009 16:29:35 +0100 Message-ID: <8a1bfe660903220829j4605306fj2382e6c169abdcbe@mail.gmail.com> Subject: Re: "iowait" bug? From: Laurent Laborde To: Laurent Wandrebeck Cc: pgsql-performance@postgresql.org 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: 200903/318 X-Sequence-Number: 33240 On Sun, Mar 22, 2009 at 8:49 AM, Laurent Wandrebeck wrote: > 2009/3/21 M. Edward (Ed) Borasky : >> I just discovered this on a LinkedIn user group: >> >> http://bugzilla.kernel.org/show_bug.cgi?id=12309 >> >> Is anyone here seeing evidence of this in PostgreSQL?? > I've been hit by an I/O wait problem, as described here: > https://bugzilla.redhat.com/show_bug.cgi?id=444759 > I've told it to that other bug, but no one seems to have followed that path. We applied this mwi patch on 3 pgsql servers, and seen great performance improvement. Using 3ware, 8 SAS HDD, Octocore (2x4) Xeon and 32GB RAM, on a custom 2.6.18 kernel. -- Laurent Laborde http://www.over-blog.com/