From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id mAUIJwY4028649 for ; Sun, 30 Nov 2008 13:19:58 -0500 Received: from mail.nosys.net (mail.nosys.net [62.93.171.218]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id mAUIJhw3000702 for ; Sun, 30 Nov 2008 13:19:44 -0500 Date: Sun, 30 Nov 2008 19:19:42 +0100 From: "J. Javier Maestro" Subject: Re: [linux-lvm] LVM snapshots overflow due to initial "overhead"? Message-ID: <20081130181942.GA11789@2jotas.com> References: <20081130160648.GA11393@2jotas.com> <20081130163733.GH13235@agk.fab.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20081130163733.GH13235@agk.fab.redhat.com> Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LVM general discussion and development On Nov Sun 30 2008 16:37, Alasdair G Kergon wrote: > On Sun, Nov 30, 2008 at 05:06:48PM +0100, J. Javier Maestro wrote: > > http://www.tldp.org/HOWTO/LVM-HOWTO/snapshots_backup.html > > **If the snapshot size equals the origin size, it will never overflow.** > > That's simply inaccurate and should be corrected. I agree with you, but it would be much more interesting to see why it is incorrect. I mean, as I mentioned in my email, why are those chunks used upfront? By doing that, the whole nice idea of a snapshot breaks completely. It would be much, much better to account for that and move those chunks out of the snapshot. -- .''`. : :' : J. Javier Maestro `. `'` `-