From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263834AbUFBS7g (ORCPT ); Wed, 2 Jun 2004 14:59:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263818AbUFBS7g (ORCPT ); Wed, 2 Jun 2004 14:59:36 -0400 Received: from mx1.redhat.com ([66.187.233.31]:26019 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S263815AbUFBS7e (ORCPT ); Wed, 2 Jun 2004 14:59:34 -0400 Date: Wed, 2 Jun 2004 19:59:24 +0100 From: Alasdair G Kergon To: Andi Kleen Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] 3/5: Device-mapper: snapshots Message-ID: <20040602185924.GS6302@agk.surrey.redhat.com> Mail-Followup-To: Andi Kleen , linux-kernel@vger.kernel.org References: <22Gkd-1AX-17@gated-at.bofh.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 02, 2004 at 08:06:06PM +0200, Andi Kleen wrote: > Alasdair G Kergon writes: > > +/*----------------------------------------------------------------- > > + * Persistent snapshots, by persistent we mean that the snapshot > > + * will survive a reboot. > > + *---------------------------------------------------------------*/ As opposed to the transient snapshot which is lost on power down. > Is this target supposed to be crash safe? What happens when > the computer crashes while writing to such a volume? The intention is for snapshot & origin still to be consistent with each other on disk. (No barriers yet, but some synchronous writes.) Alasdair -- agk@redhat.com