From owner-freebsd-hackers@FreeBSD.ORG Sun Oct 12 12:47:28 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E7B391065688 for ; Sun, 12 Oct 2008 12:47:28 +0000 (UTC) (envelope-from talon@lpthe.jussieu.fr) Received: from shiva.jussieu.fr (shiva.jussieu.fr [134.157.0.129]) by mx1.freebsd.org (Postfix) with ESMTP id 758FB8FC0C for ; Sun, 12 Oct 2008 12:47:28 +0000 (UTC) (envelope-from talon@lpthe.jussieu.fr) Received: from parthe.lpthe.jussieu.fr (parthe.lpthe.jussieu.fr [134.157.10.1]) by shiva.jussieu.fr (8.14.3/jtpda-5.4) with ESMTP id m9CCM5ia093155 for ; Sun, 12 Oct 2008 14:22:06 +0200 (CEST) X-Ids: 164 Received: from niobe.lpthe.jussieu.fr (niobe.lpthe.jussieu.fr [134.157.10.41]) by parthe.lpthe.jussieu.fr (Postfix) with ESMTP id D21958A1D3 for ; Sun, 12 Oct 2008 14:22:04 +0200 (CEST) Received: by niobe.lpthe.jussieu.fr (Postfix, from userid 2005) id BF69110A; Sun, 12 Oct 2008 14:22:04 +0200 (CEST) Date: Sun, 12 Oct 2008 14:22:04 +0200 From: Michel Talon To: freebsd-hackers@freebsd.org Message-ID: <20081012122204.GA85909@lpthe.jussieu.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.3i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (shiva.jussieu.fr [134.157.0.164]); Sun, 12 Oct 2008 14:22:06 +0200 (CEST) X-Virus-Scanned: ClamAV 0.93.3/8414/Sun Oct 12 05:30:50 2008 on shiva.jussieu.fr X-Virus-Status: Clean X-Miltered: at jchkmail2.jussieu.fr with ID 48F1CFF1.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)! X-j-chkmail-Enveloppe: 48F1CFF1.000/134.157.10.1/parthe.lpthe.jussieu.fr/parthe.lpthe.jussieu.fr/ X-j-chkmail-Score: MSGID : 48F1CFF1.000 on jchkmail2.jussieu.fr : j-chkmail score : . : R=. U=. O=. B=0.051 -> S=0.051 X-j-chkmail-Status: Ham X-Mailman-Approved-At: Sun, 12 Oct 2008 13:40:30 +0000 Subject: Re: ZFS boot X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 12 Oct 2008 12:47:29 -0000 > > It seems a bit much to reserve 1 G of memory solely for the use of the > > kernel, expecially in my case when that's all I have :) But on amd64, > > it's welcome to have terabytes of address space if it will help. > > ZFS is a memory hog, period. That's just the nature of the beast. > You probably should not be using it on a system with 1GB. I'll remind > you that memory right now is *incredibly* cheap; you can get 4GB of > brand-name lifetime-warranty RAM for around US$40-50. I am running FreeBSD-7 with the following: m.kmem_size="512M" vm.kmem_size_max="512M" vfs.zfs.arc_max="256M" vfs.zfs.arc_min="32M" vfs.zfs.prefetch_disable="1" on a i386 machine with 1 Gig memory (now upgraded to 1.5 Gig) and i have not experienced, up to now, any lockup problem. Apparently the kernel effectively uses around 500M memory, indeed. Performance seems reasonable to me, not worse than with UFS. -- Michel TALON