From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 48250C433FE for ; Wed, 29 Dec 2021 14:32:31 +0000 (UTC) Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-475-ulUr_NUQPAyvpC1aFXNoFg-1; Wed, 29 Dec 2021 09:32:25 -0500 X-MC-Unique: ulUr_NUQPAyvpC1aFXNoFg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DC3DD1853026; Wed, 29 Dec 2021 14:32:15 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5A4932B45A; Wed, 29 Dec 2021 14:32:12 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id B9EC34BB7C; Wed, 29 Dec 2021 14:31:55 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 1BTEVpwW030606 for ; Wed, 29 Dec 2021 09:31:51 -0500 Received: by smtp.corp.redhat.com (Postfix) id 83A5C140241F; Wed, 29 Dec 2021 14:31:51 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast01.extmail.prod.ext.rdu2.redhat.com [10.11.55.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7EFFB140240A for ; Wed, 29 Dec 2021 14:31:51 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6582485A5AA for ; Wed, 29 Dec 2021 14:31:51 +0000 (UTC) Received: from mail.gathman.org (mail.gathman.org [70.184.247.44]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-491-Cpc_bA2tM52GENSj9tmllg-1; Wed, 29 Dec 2021 09:31:48 -0500 X-MC-Unique: Cpc_bA2tM52GENSj9tmllg-1 Received: from wiki.gathman.org (mail.gathman.org [IPv6:2001:470:8:809::1010]) (authenticated bits=0) by mail.gathman.org (8.14.7/8.14.7) with ESMTP id 1BTDZF9X024048 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 29 Dec 2021 08:35:19 -0500 Date: Wed, 29 Dec 2021 08:35:15 -0500 (EST) From: Stuart D Gathman To: LVM general discussion and development In-Reply-To: <315E5303-D491-4487-BAD4-958420346163@gmail.com> Message-ID: <31e6126c-b6ff-42a7-68f5-a3a2782060d4@gathman.org> References: <1b906296-f66d-e755-9574-f1398bc9564@gathman.org> <315E5303-D491-4487-BAD4-958420346163@gmail.com> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 X-loop: linux-lvm@redhat.com Cc: Zdenek Kabelac Subject: Re: [linux-lvm] how to convert a disk containing a snapshot to a snapshot lv? X-BeenThere: linux-lvm@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-lvm-bounces@redhat.com Errors-To: linux-lvm-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=linux-lvm-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/mixed; boundary="-1203360521-967312667-1640784919=:23858" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---1203360521-967312667-1640784919=:23858 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by mail.gathman.org id 1BTDZF9X024048 On Tue, 28 Dec 2021, Tomas Dalebj=C3=B6rk wrote: > Yes, it is an incremental backup based of the cow device I've used such a COW based backup (can't remember the name just now, curren= tly using DRBD and rsync for incremental mirrors). The way it worked was to read and interpret the raw COW device itself and send blocks over the wire - writing directly to a volume on the remote end. It did not try to patch up metadata and use LVM to merge. You need an intimate knowledge of COW internals for either approach - BUT the read-only approach (with plain writes at the other end) is MUCH safer (not going to trash metadata at either end) and just as efficient on the wire. I've also used a block device rsync, that read every block on both sides and compared hashes - but that is obviously a lot more disk io that using the COW where LVM is already tracking changed blocks. ---1203360521-967312667-1640784919=:23858 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ ---1203360521-967312667-1640784919=:23858--