From owner-freebsd-questions@FreeBSD.ORG Mon Sep 17 17:22:30 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4F23B106566C for ; Mon, 17 Sep 2012 17:22:30 +0000 (UTC) (envelope-from jmc-freebsd2@milibyte.co.uk) Received: from avasout08.plus.net (avasout08.plus.net [212.159.14.20]) by mx1.freebsd.org (Postfix) with ESMTP id 961568FC0A for ; Mon, 17 Sep 2012 17:22:29 +0000 (UTC) Received: from curlew.milibyte.co.uk ([84.92.153.232]) by avasout08 with smtp id 0HKJ1k007516WCc01HKL7X; Mon, 17 Sep 2012 18:19:20 +0100 X-CM-Score: 0.00 X-CNFS-Analysis: v=2.0 cv=XsZ4yC59 c=1 sm=1 a=lfSX4pPLp9EkufIcToJk/A==:17 a=rLpCYgkgFLgA:10 a=ZTb9aqGL9YkA:10 a=8nJEP1OIZ-IA:10 a=D7rCoLxHAAAA:8 a=97ktiK3Q-D0A:10 a=rO8sdc0tNuqwtqtf5XIA:9 a=wPNLvfGTeEIA:10 a=lfSX4pPLp9EkufIcToJk/A==:117 Received: from curlew.lan ([192.168.1.13]) by curlew.milibyte.co.uk with esmtp (Exim 4.80) (envelope-from ) id 1TDeyc-0005HB-Aj; Mon, 17 Sep 2012 18:19:18 +0100 From: Mike Clarke To: freebsd-questions@freebsd.org Date: Mon, 17 Sep 2012 18:19:18 +0100 User-Agent: KMail/1.9.10 References: <20120917103632.GA25763@kontrol.kode5.net> <50570895.4030709@gmail.com> <20120917122014.GC25763@kontrol.kode5.net> In-Reply-To: <20120917122014.GC25763@kontrol.kode5.net> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <201209171819.18049.jmc-freebsd2@milibyte.co.uk> X-SA-Exim-Connect-IP: 192.168.1.13 X-SA-Exim-Mail-From: jmc-freebsd2@milibyte.co.uk X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on curlew.lan X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=ham version=3.3.2 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-SA-Exim-Version: 4.2 X-SA-Exim-Scanned: Yes (on curlew.milibyte.co.uk) Cc: Jamie Paul Griffin Subject: Re: Questions about ZFS Tuning X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Sep 2012 17:22:30 -0000 On Monday 17 September 2012 13:20:14 Jamie Paul Griffin wrote: > I set zfs.zfs.prefetch_disable=0 because some dmesg line suggested/implied > it would benefit. I don't recall the exact output now. If you look in /var/run/dmesg.boot you should find the message saying "ZFS NOTICE: Prefetch is disabled by default if less than 4GB of RAM is present; to enable, add "vfs.zfs.prefetch_disable=0" to /boot/loader.conf." Since you have 2GB RAM then it's best to leave things as they are with prefetch disabled. -- Mike Clarke