From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:36348) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TiO4p-00017p-Vv for qemu-devel@nongnu.org; Tue, 11 Dec 2012 06:32:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TiO4k-0000aw-7h for qemu-devel@nongnu.org; Tue, 11 Dec 2012 06:32:43 -0500 Received: from mail-we0-f173.google.com ([74.125.82.173]:59567) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TiO4k-0000as-2X for qemu-devel@nongnu.org; Tue, 11 Dec 2012 06:32:38 -0500 Received: by mail-we0-f173.google.com with SMTP id z2so1625729wey.4 for ; Tue, 11 Dec 2012 03:32:37 -0800 (PST) Date: Tue, 11 Dec 2012 12:32:34 +0100 From: Stefan Hajnoczi Message-ID: <20121211113234.GH796@stefanha-thinkpad.muc.redhat.com> References: <1353935123-24199-1-git-send-email-benoit@irqsave.net> <1353935123-24199-2-git-send-email-benoit@irqsave.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1353935123-24199-2-git-send-email-benoit@irqsave.net> Subject: Re: [Qemu-devel] [RFC V3 01/24] qcow2: Add deduplication to the qcow2 specification. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?iso-8859-1?Q?Beno=EEt?= Canet Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com On Mon, Nov 26, 2012 at 02:05:00PM +0100, Benoît Canet wrote: > +== Deduplication table == > + > +The deduplication table contains 64 bits offsets to the level 2 deduplication > +table clusters. > +Each entry of these clusters contains a 32 bytes SHA256 hash followed by the > +64 bits logical offset of the first encountered block having this hash. Can you foresee the need to use a different hash algorithm in the future and should we add a hash_algo enum field to the dedup QCOW2 header extension? Stefan