From owner-freebsd-fs@FreeBSD.ORG  Fri May 25 13:24:19 2012
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
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 BB8F91065670
	for <freebsd-fs@freebsd.org>; Fri, 25 May 2012 13:24:19 +0000 (UTC)
	(envelope-from feld@feld.me)
Received: from feld.me (unknown [IPv6:2607:f4e0:100:300::2])
	by mx1.freebsd.org (Postfix) with ESMTP id 858F18FC19
	for <freebsd-fs@freebsd.org>; Fri, 25 May 2012 13:24:19 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=feld.me;
	s=blargle; 
	h=Message-Id:From:Mime-Version:Subject:Date:To:Content-Type;
	bh=fq/+7hwgJBa+J+xmGHdJqOHgJT++g8MPL8t5QrAq1tM=; 
	b=kziFl88JxizE07TX8K4uOnbU/+Wj9uFLuYoAHRHVmta/XQvPSSU3PhyGuR3+k1aU/U5sUJ+eYI4Cv4l7N/JcDjfFCpMKgqmJ4rbZtzQ/ryhqXYzt9Dy12yOdGT+EzMhy;
Received: from localhost ([127.0.0.1] helo=mwi1.coffeenet.org)
	by feld.me with esmtp (Exim 4.77 (FreeBSD))
	(envelope-from <feld@feld.me>) id 1SXuV8-000Ma3-Dr
	for freebsd-fs@freebsd.org; Fri, 25 May 2012 08:24:19 -0500
Received: from feld@feld.me by mwi1.coffeenet.org (Archiveopteryx 3.1.4)
	with esmtpa id 1337952252-3288-3287/5/26; Fri, 25 May 2012 13:24:12
	+0000
Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes
To: freebsd-fs@freebsd.org
Date: Fri, 25 May 2012 08:24:11 -0500
Mime-Version: 1.0
From: Mark Felder <feld@feld.me>
Message-Id: <op.weu8uleu34t2sn@tech304>
User-Agent: Opera Mail/11.64 (FreeBSD)
X-SA-Score: -1.0
Subject: UFS SUJ and fsck questions
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 25 May 2012 13:24:19 -0000

Hi guys,

I'm building out a highly available storage backend with HAST+NFS on UFS.  
So far I've encountered a node going down and the filesystem being dirty,  
so the other side won't mount it automatically. I've resolved this issue  
with the following before the mount:

fsck -C -t ufs -y /dev/hast/${disk}

However, the problem is that on a disk nearly 1TB in size it will take a  
long time to fsck and the failover won't be as smooth. SUJ would fit the  
bill here pretty well. My main issue is not understanding the interaction  
between SUJ and fsck.

If I simply try to mount a fs with SUJ, it will do the SUJ magic if  
necessary and move on. But what if it's damaged beyond what SUJ can handle  
and needs a real fsck? Can I use the same procedure? Will executing `fsck  
-C` against an SUJ enabled filesystem that hasn't run the SUJ journal yet  
do that first and exit if the journal replay was successful? If not, does  
anyone have any ideas on how I can detect that automatically so I can get  
the filesystem mounted cleanly without human intervention?


Thanks!