From owner-freebsd-questions@FreeBSD.ORG Fri Aug 19 02:37:15 2011 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F16431065672 for ; Fri, 19 Aug 2011 02:37:15 +0000 (UTC) (envelope-from perryh@pluto.rain.com) Received: from agora.rdrop.com (agora.rdrop.com [IPv6:2607:f678:1010::34]) by mx1.freebsd.org (Postfix) with ESMTP id B9D438FC15 for ; Fri, 19 Aug 2011 02:37:15 +0000 (UTC) Received: from agora.rdrop.com (66@localhost [127.0.0.1]) by agora.rdrop.com (8.13.1/8.12.7) with ESMTP id p7J2bCep008178 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Thu, 18 Aug 2011 19:37:12 -0700 (PDT) (envelope-from perryh@pluto.rain.com) Received: (from uucp@localhost) by agora.rdrop.com (8.13.1/8.12.9/Submit) with UUCP id p7J2bCRY008177; Thu, 18 Aug 2011 19:37:12 -0700 (PDT) Received: from fbsd81 ([192.168.200.81]) by pluto.rain.com (4.1/SMI-4.1-pluto-M2060407) id AA12541; Thu, 18 Aug 11 19:35:37 PDT Date: Fri, 19 Aug 2011 02:35:18 -0700 From: perryh@pluto.rain.com To: conrads@cox.net Message-Id: <4e4e2e56.bMLoyidwVf4PG00s%perryh@pluto.rain.com> References: <20110818174341.65a0859b@cox.net> In-Reply-To: <20110818174341.65a0859b@cox.net> User-Agent: nail 11.25 7/29/05 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: Enabling gjournal without destroying a filesystem? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Aug 2011 02:37:16 -0000 "Conrad J. Sabatier" wrote: > Is there any way to enable gjournal on an already existing > filesystem without destroying it? Yes, provided the existing filesystem is not using the last block of its provider (partition), but you'll have to put the journal on a separate provider from the data. See the explanation of the -s switch in gjournal(8) to determine the necessary size of the journal provider, but don't specify -s in the "gjournal label" command because the size of the journal is implicitly set by the the size of its provider when separate from the data provider. (-s is used when a single provider is used for both journal and data.) Also read the explanation of the -f switch, but don't actually specify -f unless you are sure you know what you're doing :) Something like this [untested]: # umount [existing filesystem] # gjournal label [existing filesystem] [journal provider] # tunefs -J enable -n disable [existing filesystem].journal # mount -o async [existing filesystem].journal [mountpoint] and edit /etc/fstab accordingly.