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 m9T0Xh1V005524 for ; Tue, 28 Oct 2008 20:33:43 -0400 Received: from mail.unpatched.net (mail.unpatched.net [80.179.151.65]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id m9T0WYx9018337 for ; Tue, 28 Oct 2008 20:32:34 -0400 Received: from [192.168.13.77] (localhost [127.0.0.1]) by mail.unpatched.net (Postfix) with ESMTP id 52826D40FF for ; Wed, 29 Oct 2008 02:11:59 +0200 (IST) Message-ID: <4907AF21.4030808@hidden.domain.name> Date: Wed, 29 Oct 2008 02:32:33 +0200 From: Yoav MIME-Version: 1.0 Subject: Re: [linux-lvm] mirror and snapshot incompatible References: <490678BE.1070700@hidden.domain.name> <08781647-26E4-46F3-B148-A64933B84363@redhat.com> In-Reply-To: <08781647-26E4-46F3-B148-A64933B84363@redhat.com> Content-Transfer-Encoding: 7bit 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"; format="flowed" To: LVM general discussion and development I know how to do it through device-mapper. I'm just worried that maybe there's a reason why lvm prevents it. Are you aware of such reason, or is it safe? Jonathan Brassow wrote: > It is possible to do all the things you are asking through > device-mapper... but there is no easy way to do it. (and LVM does not > yet have the capabilities to manage this yet either.) > > brassow > > On Oct 27, 2008, at 9:28 PM, Yoav wrote: > >> According to lvcreate, a snapshot of a mirrored volume cannot be >> created ("Snapshots and mirrors may not yet be mixed"). However, >> devmapper does not seem to have the same limitation when used >> directly (not through lvm). >> >> Is there a current reason for lvcreate to enforce this rather harsh >> limitation? >> >> What are the risks I'm taking by manually creating a dm-snapshot from >> a dm-mirror device? (of course I'm also replacing the dm-mirror >> device with a snapshot-origin of the actual dm-mirror device). >> >> If there is an actual reason for preventing this, what is the >> suggested way to consistently backup a mirror volume? Is there a way >> to temporarily take one of the mirror "legs" (mimage devices) >> offline in order to back it up, and resync it later? >> >> Yoav >> >> _______________________________________________ >> linux-lvm mailing list >> linux-lvm@redhat.com >> https://www.redhat.com/mailman/listinfo/linux-lvm >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/