From owner-freebsd-geom@FreeBSD.ORG Thu Jan 25 16:56:04 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 AD29616A400; Thu, 25 Jan 2007 16:56:04 +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 7FF7B13C448; Thu, 25 Jan 2007 16:56:04 +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 l0PGu0mQ077235; Thu, 25 Jan 2007 10:56:01 -0600 (CST) (envelope-from anderson@freebsd.org) Message-ID: <45B8E121.2000701@freebsd.org> Date: Thu, 25 Jan 2007 10:56:01 -0600 From: Eric Anderson User-Agent: Thunderbird 1.5.0.9 (X11/20070121) MIME-Version: 1.0 To: Oliver Fromme References: <200701251057.l0PAvnBR092070@lurza.secnetix.de> In-Reply-To: <200701251057.l0PAvnBR092070@lurza.secnetix.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.88.4/2489/Thu Jan 25 06:35:24 2007 on mh1.centtech.com X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=8.0 tests=AWL,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, Mike Silbersack , 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: Thu, 25 Jan 2007 16:56:05 -0000 On 01/25/07 04:57, Oliver Fromme wrote: > Mike Silbersack wrote: > > Eric Anderson wrote: > > > > > Why not disable swap, use the swap partition as the new journaling device, > > > and then enable vn-backed swap for the system? > > > > I wouldn't want to disable swap, > > Eric didn't say to disable swap permanently. Only disable > the existing swap partition (use swapoff(8)) and then use > it for the journal. Then create a swap file in an existing > file system and use that one for swapping. > > > but if I could use some percentage of swap, then it would rock. > > That would be possible, too, of course. Disable swapping > temporarily with swapoff(8), then shrink the swap partition > with bsdlabel(8) and create a new partition in the free > space. Then resume swapping with swapon(8) on the swap > partition (which is now smaller), and use the new partition > for the journal. If swap is now too small, you can still > create an additional swap file in an existing file system, > of course. > > However, note that the journal requires a certain minimum > size which depends on the thoughput of data on that file > system. I guess that half of the swap partition would be > too small in many common cases. > > Unfortunately, FreeBSD doesn't have shrinkfs(8), which > would be extremely useful to add space for a journal to > an existing disk (among other things). Maybe this is > something that should be added to the ideas web page. > > Best regards > Oliver > I think you could also reduce the journaling sync time for gjournal to reduce the needed journal size, but pjd@ would be best to answer that one. Eric