From owner-freebsd-fs@FreeBSD.ORG Thu Jan 10 10:19:09 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 6DA2DF80; Thu, 10 Jan 2013 10:19:09 +0000 (UTC) (envelope-from joh.hendriks@gmail.com) Received: from mail-la0-f42.google.com (mail-la0-f42.google.com [209.85.215.42]) by mx1.freebsd.org (Postfix) with ESMTP id AAE8F1BA; Thu, 10 Jan 2013 10:19:08 +0000 (UTC) Received: by mail-la0-f42.google.com with SMTP id fe20so366183lab.29 for ; Thu, 10 Jan 2013 02:19:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:message-id:date:from:user-agent:mime-version:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding; bh=gmz+r/uBENz93P46MFoCZCaVj3lowUw2GwX6/B4x2xo=; b=P4nmLRShcGywudxHu/5ECOOS/7FIckeqH+7i6wmt1tmKrFbKIh6SpAZofnGdNiZO1a HQmnaICLpsVxXPwt7I8TnULXpw81H6HTG1Cj/yGaxOx59niJhNIp2I+I2LFGtyQDYzhs /mVl79C6rZhkugDxcouvSRsXbCN9tfYGH38uUvBZAwRE1uBz0p11nwMijP9DBS1ObiY2 NdVsWjoQnX75EtEjbg2gHl2JmSt4EkRuzsVzGvQrtunpHDtYrFW5VxQ1gLG2VrQ0aCX3 x+ZOv45jgSp2xV8ey3Ap+6250sw80oT7KrabIR9Faqwt7Vvt5Pzq0+CabrAW5OFWopIU yhog== X-Received: by 10.152.145.37 with SMTP id sr5mr11252559lab.33.1357813141927; Thu, 10 Jan 2013 02:19:01 -0800 (PST) Received: from [192.168.1.129] (schavemaker.nl. [213.84.84.186]) by mx.google.com with ESMTPS id ml1sm443992lab.15.2013.01.10.02.18.59 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 10 Jan 2013 02:19:00 -0800 (PST) Message-ID: <50EE9592.8050903@gmail.com> Date: Thu, 10 Jan 2013 11:18:58 +0100 From: Johan Hendriks User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 To: Artem Belevich Subject: Re: rc.d script for memory based zfs intent log References: <20130109023327.GA1888@FreeBSD.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-fs@freebsd.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Jan 2013 10:19:09 -0000 Artem Belevich schreef: > On Wed, Jan 9, 2013 at 7:15 AM, Borja Marcos wrote: >> In case of a crash, seems to be riskier than using sync=disabled on the datasets you need. What is the impact on the data integrity of a suddenly disappearing ZIL? > Losing ZIL used to be fatal for the pool. > I think in recent ZFS versions (v28?) you will only lose transactions > that were not committed to the pool yet, but don't quote me on that. > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" Loosing the ZIL will loose data written to the ZIL not jet flushed to the pool itself. So most likely you will have corrupted data. So for a ZIL use a mirror pair! You can add and remove a ZIL from the pool without problem from version 28 and above. Same thing goes if you have sync=disabled. Data acknowledge by the server but not flushed to the pool will end up in corrupt data. Disabeling sync is something you do not want to do. If you need, use the ZIL. regards Johan Hendriks Neuteboom Automatisering