From owner-freebsd-stable@FreeBSD.ORG Tue Feb 22 11:17:32 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0E71C106564A for ; Tue, 22 Feb 2011 11:17:32 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta09.emeryville.ca.mail.comcast.net (qmta09.emeryville.ca.mail.comcast.net [76.96.30.96]) by mx1.freebsd.org (Postfix) with ESMTP id E114B8FC14 for ; Tue, 22 Feb 2011 11:17:31 +0000 (UTC) Received: from omta23.emeryville.ca.mail.comcast.net ([76.96.30.90]) by qmta09.emeryville.ca.mail.comcast.net with comcast id AzHX1g0011wfjNsA9zHX68; Tue, 22 Feb 2011 11:17:31 +0000 Received: from koitsu.dyndns.org ([98.248.33.18]) by omta23.emeryville.ca.mail.comcast.net with comcast id AzHV1g0070PUQVN8jzHWTn; Tue, 22 Feb 2011 11:17:30 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 68A449B422; Tue, 22 Feb 2011 03:17:29 -0800 (PST) Date: Tue, 22 Feb 2011 03:17:29 -0800 From: Jeremy Chadwick To: Bruce Cran Message-ID: <20110222111729.GA193@icarus.home.lan> References: <1297026074.23922.8.camel@ubuntu> <20110207045501.GA15568@icarus.home.lan> <1297065041.754.12.camel@ubuntu> <20110207085537.GA20545@icarus.home.lan> <1298372700.4940.76.camel@debian.nessbank> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1298372700.4940.76.camel@debian.nessbank> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Greg Bonett , freebsd-stable Subject: Re: 8.1 amd64 lockup (maybe zfs or disk related) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Feb 2011 11:17:32 -0000 On Tue, Feb 22, 2011 at 11:05:00AM +0000, Bruce Cran wrote: > On Mon, 2011-02-07 at 00:55 -0800, Jeremy Chadwick wrote: > > > # NOTE: Systems with 8GB of RAM or more have prefetch enabled by default. > > vfs.zfs.prefetch_disable="1" > > I think ZFS is enabled with 4 GB or more, not 8 GB: > > "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." The message ZFS on FreeBSD spits out (shown above) is somewhat inaccurate. I spent the time looking at the code and blogged about the condition over a year ago: http://koitsu.wordpress.com/2009/10/12/testing-out-freebsd-8-0-rc1/ Search for "ZFS NOTICE: system has less than 4GB" on the page above. I still feel the message needs to be re-worded, despite having gone through multiple changes of phrasing already. -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP 4BD6C0CB |