From owner-freebsd-fs@FreeBSD.ORG Wed Sep 1 09:11:42 2010 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 2DF0410656BC for ; Wed, 1 Sep 2010 09:11:42 +0000 (UTC) (envelope-from k0802647@telus.net) Received: from defout.telus.net (defout.telus.net [204.209.205.13]) by mx1.freebsd.org (Postfix) with ESMTP id DE2BF8FC15 for ; Wed, 1 Sep 2010 09:11:41 +0000 (UTC) Received: from edmwaa03.telusplanet.net ([66.183.53.162]) by priv-edmwes24.telusplanet.net (InterMail vM.7.09.01.00 201-2219-108-20080618) with ESMTP id <20100901091140.XQLJ16905.priv-edmwes24.telusplanet.net@edmwaa03.telusplanet.net> for ; Wed, 1 Sep 2010 03:11:40 -0600 Received: from oliver.bc.lan (d66-183-53-162.bchsia.telus.net [66.183.53.162]) by edmwaa03.telusplanet.net (BorderWare Security Platform) with ESMTP id 93B92256E7C3E3E8 for ; Wed, 1 Sep 2010 03:11:40 -0600 (MDT) Received: from [10.111.111.112] (unknown [10.111.111.112]) by oliver.bc.lan (Postfix) with ESMTP id 2654D6455; Wed, 1 Sep 2010 02:11:40 -0700 (PDT) Message-ID: <4C7E18CB.7020400@telus.net> Date: Wed, 01 Sep 2010 02:11:39 -0700 From: Carl User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.7) Gecko/20100713 Lightning/1.0b2 Thunderbird/3.1.1 MIME-Version: 1.0 To: freebsd-fs@freebsd.org References: <4C7CE2D0.40400@telus.net> In-Reply-To: <4C7CE2D0.40400@telus.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Cloudmark-Analysis: v=1.1 cv=SJIhyCEJBCHyullCFvS0mIdE5QsJS0d45teFqlr0wtg= c=1 sm=0 a=-TCISbd4vvQA:10 a=8nJEP1OIZ-IA:10 a=HNgjH8kF64GtJ7EcXKEMsQ==:17 a=TSbVqHtbAAAA:8 a=ovWl91bCEESMzyah8xIA:9 a=fiiRb9nCYlAv-_QnrpUA:7 a=1JQRu8pM5reU-8oiI3I0w186ZlQA:4 a=wPNLvfGTeEIA:10 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 Subject: Re: gjournal alignment on 4K sector advanced format drives 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, 01 Sep 2010 09:11:42 -0000 On Tue Aug 31 12:19:52 UTC 2010, Ivan Voras wrote: > On 08/31/10 13:09, Carl wrote: >> Now I want to add gjournal to some of my partitions. It seems to me that >> I must also ensure the journal is aligned just as I've done with the >> data. So far, though, I have found no information as to how the >> journal's own filesystem layout works. Does it use fixed size >> blocks/fragments like the UFS2 data does? If so, what is its minimum >> addressable unit size? If it is smaller than 4KiB, we get journal >> misalignment and a performance loss, right? What must I do to ensure the >> journal is fully aligned? > > gjournal writes its metadata throughout the journal in sector sizes (512 > bytes) so it cannot be aligned in this way. > > For this you need a solution which will actually change the sector size, > like gnop or my glabel patch. From the following discussion, the glabel patch isn't likely to get committed, in which case I can't use it: http://comments.gmane.org/gmane.os.freebsd.devel.hackers/40664 Correct me if I'm wrong, but the gnop solution is still non-persistent and therefore unavailable for partitions whose mounting cannot be delayed till after startup scripts have executed. I'm not knowledgeable enough about this, so I'd welcome a clear description of how to reliably and automatically use gnop to override sector size at boot time. It sounds like neither ZFS nor gjournal are suitable for a production server with WDxxEARS drives. Soft updates and horribly long fsck times is the only option? A pox on Western Digital for delivering drives that lie about sector size >:-< Carl / K0802647