From owner-freebsd-fs@FreeBSD.ORG Wed Mar 2 08:57:35 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9F131106564A for ; Wed, 2 Mar 2011 08:57:35 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from mail.ebusiness-leidinger.de (mail.ebusiness-leidinger.de [217.11.53.44]) by mx1.freebsd.org (Postfix) with ESMTP id 5129F8FC0A for ; Wed, 2 Mar 2011 08:57:35 +0000 (UTC) Received: from outgoing.leidinger.net (p5B32E950.dip.t-dialin.net [91.50.233.80]) by mail.ebusiness-leidinger.de (Postfix) with ESMTPSA id A735B844015; Wed, 2 Mar 2011 09:57:31 +0100 (CET) Received: from webmail.leidinger.net (unknown [IPv6:fd73:10c7:2053:1::2:102]) by outgoing.leidinger.net (Postfix) with ESMTP id 6EB7221F0; Wed, 2 Mar 2011 09:57:28 +0100 (CET) Received: (from www@localhost) by webmail.leidinger.net (8.14.4/8.13.8/Submit) id p228vCLI096409; Wed, 2 Mar 2011 09:57:12 +0100 (CET) (envelope-from Alexander@Leidinger.net) Received: from pslux.ec.europa.eu (pslux.ec.europa.eu [158.169.9.14]) by webmail.leidinger.net (Horde Framework) with HTTP; Wed, 02 Mar 2011 09:57:12 +0100 Message-ID: <20110302095712.129650oisvocoq4o@webmail.leidinger.net> Date: Wed, 02 Mar 2011 09:57:12 +0100 From: Alexander Leidinger To: Dr Josef Karthauser References: <0E00DAFC-C39F-47DC-B9AF-16419C20997F@tao.org.uk> <615F1346-E830-42E2-B229-4181B8BC56BD@exonetric.com> <53FA69D2-2EF0-4CBF-985B-6E710F15FE02@tao.org.uk> <20110302001650.GB49147@icarus.home.lan> In-Reply-To: <20110302001650.GB49147@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit User-Agent: Dynamic Internet Messaging Program (DIMP) H3 (1.1.4) X-EBL-MailScanner-Information: Please contact the ISP for more information X-EBL-MailScanner-ID: A735B844015.A4926 X-EBL-MailScanner: Found to be clean X-EBL-MailScanner-SpamCheck: not spam, spamhaus-ZEN, SpamAssassin (not cached, score=1.351, required 6, autolearn=disabled, RDNS_NONE 1.27, TW_ZF 0.08) X-EBL-MailScanner-SpamScore: s X-EBL-MailScanner-From: alexander@leidinger.net X-EBL-MailScanner-Watermark: 1299661052.07987@VexDM1/JqGwVK6GB3BHYfg X-EBL-Spam-Status: No Cc: freebsd-fs@freebsd.org Subject: Re: ZFS on a single disk? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Mar 2011 08:57:35 -0000 Quoting Jeremy Chadwick (from Tue, 1 Mar 2011 16:16:50 -0800): > On Wed, Mar 02, 2011 at 12:00:24AM +0000, Dr Josef Karthauser wrote: >> On 1 Mar 2011, at 23:49, Mark Blackman wrote: >> > >> > On 1 Mar 2011, at 23:27, Dr Josef Karthauser wrote: >> > >> >> Does it make sense to run zfs on a single disk? >> >> >> >> I'm setting up a FreeBSD host over at a Xen provider, with a >> single 80GB disk image. Ideally I'd like to run ZFS on this system, >> for snapshot and flexible creation of filesystems and quotas. Has >> anyone got any recommendations for me in this regard? Am I crazy? >> > >> > Not crazy, I do this as well, all the time just to get the >> management capabilities and >> > leave hardware RAID to manage the availability. >> > >> > - Mark >> >> Any idea what the performance implications are? Can I get away >> without a ZIL or ARC and still get a decent performance? > > Do not disable the ZIL. I hate referring to the Solaris documentation > for FreeBSD, but it applies: > > http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Disabling_the_ZIL_.28Don.27t.29 > > And you cannot disable the ARC, so just tune it appropriately (which > you'll need to do on FreeBSD anyway). In fact, by getting rid of the > ARC (as you proposed), you would suffer worse performance than if you > had it in use. If you are not satisfied with the performance, you can add a USB memory stick as a cache device to the pool. See the following link to get a glue about what to expect and when it makes sense and when not: http://www.leidinger.net/blog/2010/02/10/making-zfs-faster/ Bye, Alexander. -- To add insult to injury. -- Phaedrus http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137