From owner-freebsd-performance@FreeBSD.ORG Sat Dec 17 15:25:43 2011 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 04A2E1065670; Sat, 17 Dec 2011 15:25:43 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-ww0-f42.google.com (mail-ww0-f42.google.com [74.125.82.42]) by mx1.freebsd.org (Postfix) with ESMTP id 610E78FC13; Sat, 17 Dec 2011 15:25:42 +0000 (UTC) Received: by wgbds13 with SMTP id ds13so4794938wgb.1 for ; Sat, 17 Dec 2011 07:25:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=nTbyBdzJWT2Qwt/qaMF3tXrKYw9o7fE/LlrR5k4ZW0E=; b=oxmv7q+UsG3BLkSpzjtpdoDJg91iHh7ZkGkpC6yETjKJBG6mGK3GXKQgG8SdDsq0RT xnWyuaC9qfArey2EYSuN0FjFDCa0wJEgym3ptmU9PHG02VH8B/amCBx6oNoadbHsm0pM dABXJSWr2bLL76984Hyui8wzNIKqEl58sPvGI= MIME-Version: 1.0 Received: by 10.180.82.138 with SMTP id i10mr4497808wiy.2.1324133980360; Sat, 17 Dec 2011 06:59:40 -0800 (PST) Received: by 10.223.156.132 with HTTP; Sat, 17 Dec 2011 06:59:40 -0800 (PST) In-Reply-To: <4EEC9890.7040806@FreeBSD.org> References: <4EEC9890.7040806@FreeBSD.org> Date: Sat, 17 Dec 2011 08:59:40 -0600 Message-ID: From: Adam Vande More To: Martin Matuska Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-performance@freebsd.org Subject: Re: PostgreSQL user experience: FreeBSD (ZFS) vs OpenIndiana (ZFS) vs Linux (EXT4) X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Dec 2011 15:25:43 -0000 On Sat, Dec 17, 2011 at 7:26 AM, Martin Matuska wrote: > I would like to share some of our expreience with PostgreSQL on FreeBSD. > It has been a while ago since we had to stop using FreeBSD for our > customer's PostgreSQL servers. > I don't claim any expertise in this area so please take this with that in mind. A couple of things that might help. Setting zfs set sync=disabled on fs where the WAL resides(all alone). Of course this would help ZFS regardless of OS. http://www.postgresql.org/docs/8.4/static/wal-intro.html I've also seen other reports of slow PostgreSQL on FreeBSD, and in that scenario there were a large amount of gettimeofday(2) calls as the bottleneck and such calls on FreeBSD are significantly slower. http://postgresql.1045698.n5.nabble.com/Postgresql-9-0-2-explain-analyze-very-slow-10x-compared-to-actual-query-time-td3336664.html If you have a faster timecounter, it might help to switch. -- Adam Vande More