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 m53NcPqr025116 for ; Tue, 3 Jun 2008 19:38:26 -0400 Received: from server.klug.on.ca (server.klug.on.ca [205.189.48.131]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id m53Nc9nf015843 for ; Tue, 3 Jun 2008 19:38:09 -0400 Received: from linux.interlinx.bc.ca (unknown [67.193.220.102]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by server.klug.on.ca (Postfix) with ESMTP id 05EAF2803 for ; Tue, 3 Jun 2008 19:38:08 -0400 (EDT) Received: from [10.75.22.1] (pc.ilinx [10.75.22.1]) by linux.interlinx.bc.ca (Postfix) with ESMTP id 006508710 for ; Tue, 3 Jun 2008 19:38:06 -0400 (EDT) Subject: Re: [linux-lvm] ANNOUNCE: an experimental implementation of snapshot merging From: "Brian J. Murrell" In-Reply-To: <1212525819.19122.16.camel@behemoth.csg.stercomm.com> References: <1212525819.19122.16.camel@behemoth.csg.stercomm.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-OfBhZd6dlofbEnQWYesu" Date: Tue, 03 Jun 2008 19:38:06 -0400 Message-Id: <1212536286.29076.202.camel@pc.ilinx> Mime-Version: 1.0 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: To: LVM general discussion and development --=-OfBhZd6dlofbEnQWYesu Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2008-06-03 at 15:43 -0500, Chris Cox wrote: >=20 > I would think this would be VERY hard to do since both the "origin" and > "snapshot" change (file deletes, etc). I don't think it's as difficult as you are thinking it is. You are thinking of synchronizing filesystems, at the filesystem level, but merging a snapshot back up into the origin does not deal with files or even filesystems. It deals with block devices and blocks, and is really nothing more than a coordinated: for each COW_block in snapshot; do for other_snapshot of origin; do copy origin[COW_block] to other_snapshot[COW_block] copy snapshot[COW_block] to origin[COW_block] done done > Do you have a set of rules you > use for the merge? There is no filesystem level merge. There are no rules needed. b. --=-OfBhZd6dlofbEnQWYesu Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBIRdXel3EQlGLyuXARAsdHAJ9mhqY6F/boW1skZ07gNjgl0nHsbgCdENwn 2moZx0aTD8v8gfVOE1jElGg= =XrCA -----END PGP SIGNATURE----- --=-OfBhZd6dlofbEnQWYesu--