From owner-freebsd-current@FreeBSD.ORG Wed Jul 25 22:20:37 2007 Return-Path: Delivered-To: current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EFB1116A419 for ; Wed, 25 Jul 2007 22:20:37 +0000 (UTC) (envelope-from craig@xfoil.gank.org) Received: from ion.gank.org (ion.gank.org [69.55.238.164]) by mx1.freebsd.org (Postfix) with ESMTP id BA01613C465 for ; Wed, 25 Jul 2007 22:20:37 +0000 (UTC) (envelope-from craig@xfoil.gank.org) Received: by ion.gank.org (Postfix, from userid 1001) id 7301411253; Wed, 25 Jul 2007 17:20:37 -0500 (CDT) Date: Wed, 25 Jul 2007 17:20:35 -0500 From: Craig Boston To: Dmitry Morozovsky Message-ID: <20070725222035.GA50522@nowhere> Mail-Followup-To: Craig Boston , Dmitry Morozovsky , Pawel Jakub Dawidek , current@FreeBSD.org References: <20070725234322.G33266@woozle.rinet.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070725234322.G33266@woozle.rinet.ru> User-Agent: Mutt/1.4.2.3i Cc: Pawel Jakub Dawidek , current@FreeBSD.org Subject: Re: ZFS on a notebook/512M settings X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Jul 2007 22:20:38 -0000 On Thu, Jul 26, 2007 at 12:52:33AM +0400, Dmitry Morozovsky wrote: > I want to join the 'eating our own dogfood' company using ZFS on my notebook. > However, it is armed with only 512M of RAM. What are tunings which would > possibly keep it from panicing? For now, I've got in /boot/loader.conf: I'm using /boot/loader.conf: vm.kmem_size="268435456" vfs.zfs.prefetch_disable="1" /etc/sysctl.conf: kern.maxvnodes=22500 on my home fileserver with 512MB of RAM without incident. It does a lot of small file access -- cvsup's RELENG_4, RELENG_6, and HEAD sources nightly and imports them into subversion. You could probably bump up maxvnodes a little without it panicing. I started conservatively and performance has been acceptable so I haven't taken the time to tune it fully. I've seen recommendations on the BSD lists to use zil_disable to avoid low-memory deadlocks (which I've not yet encountered). I've also seen dire warnings on the OpenSolaris lists about possible data corruption if you disable the ZIL, so I'm unsure about that one. For now I'm erring on the side of caution and leaving it enabled until it causes me problems. Craig