From owner-freebsd-geom@FreeBSD.ORG Tue Jan 23 14:58:25 2007 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id F1B6016A400; Tue, 23 Jan 2007 14:58:25 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from mh1.centtech.com (moat3.centtech.com [64.129.166.50]) by mx1.freebsd.org (Postfix) with ESMTP id C2D1E13C480; Tue, 23 Jan 2007 14:58:25 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from [10.177.171.220] (neutrino.centtech.com [10.177.171.220]) by mh1.centtech.com (8.13.8/8.13.8) with ESMTP id l0NEwNbl049255; Tue, 23 Jan 2007 08:58:23 -0600 (CST) (envelope-from anderson@freebsd.org) Message-ID: <45B62293.9020907@freebsd.org> Date: Tue, 23 Jan 2007 08:58:27 -0600 From: Eric Anderson User-Agent: Thunderbird 1.5.0.9 (X11/20070121) MIME-Version: 1.0 To: Oliver Fromme References: <200701231435.l0NEZ7W4049331@lurza.secnetix.de> In-Reply-To: <200701231435.l0NEZ7W4049331@lurza.secnetix.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.88.4/2480/Tue Jan 23 05:21:51 2007 on mh1.centtech.com X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=8.0 tests=BAYES_00 autolearn=ham version=3.1.6 X-Spam-Checker-Version: SpamAssassin 3.1.6 (2006-10-03) on mh1.centtech.com Cc: vd@freebsd.org, silby@silby.com, xride@x12.dk, freebsd-geom@freebsd.org Subject: Re: Where to start? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Jan 2007 14:58:26 -0000 On 01/23/07 08:35, Oliver Fromme wrote: > Eric Anderson wrote: > > Oliver Fromme wrote: > > > Vasil Dimov wrote: > > > > This thing still looks to me like roping your chest to your leg (instead > > > > of to an unmovable object) in order to avoid falling, but I might be > > > > wrong... > > > > > > True, it's certainly not a clean nor efficient solution. > > > But Mike has a valid point that it would enable people to > > > turn on journaling on existing file systems, without the > > > need for repartitioning or adding a disk. It would be a > > > nice way to _quickly_ set up journaling, for testing > > > purposes, or simply for curiosity. > > > > Why not disable swap, use the swap partition as the new journaling > > device, and then enable vn-backed swap for the system? > > Nice idea. Indeed, that would probably work, if the swap > is large enough to hold the journal. > > By the way, what happens if you put a swap file on a > journaled file system? Will the page-out actions also > be journaled? Yep. gjournal has no way to know (right now) that it is journaling a swap file, etc. It's just a block device journal, so anything that hits the disk, goes through the journal. I'm not sure how this impacts performance, if it does at all. > > > BTW, I think in Solaris you can also add journaling to an > > > existing UFS partition on the fly, without the need for > > > newfs or adding space. (Provided that there is enough > > > free space inside the existing file system, of course.) > > > > Sure - many journaling fs have that ability. There's been several > > attempts in the past to add journaling to our UFS2, without completion. > > Yes, I know. But now there is PJD's gjournal. :-) > > Best regards > Oliver > Eric