From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay6-d.mail.gandi.net ([217.70.183.198]:58557 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932726AbaDILP3 convert rfc822-to-8bit (ORCPT ); Wed, 9 Apr 2014 07:15:29 -0400 Received: from mfilter7-d.gandi.net (mfilter7-d.gandi.net [217.70.178.136]) by relay6-d.mail.gandi.net (Postfix) with ESMTP id 93B0BFB8BF for ; Wed, 9 Apr 2014 13:15:27 +0200 (CEST) Received: from relay6-d.mail.gandi.net ([217.70.183.198]) by mfilter7-d.gandi.net (mfilter7-d.gandi.net [10.0.15.180]) (amavisd-new, port 10024) with ESMTP id rApdKfn8zOqv for ; Wed, 9 Apr 2014 13:15:26 +0200 (CEST) Received: from zafu.localnet (dhcp230.cr2i.univ-montp2.fr [162.38.105.230]) (Authenticated sender: michel@bouissou.net) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id DB852FB874 for ; Wed, 9 Apr 2014 13:15:25 +0200 (CEST) From: =?ISO-8859-1?Q?Sw=E2mi?= Petaramesh To: linux-btrfs@vger.kernel.org Subject: Using noCow with snapshots ? Date: Wed, 09 Apr 2014 13:15:24 +0200 Message-ID: <1541415.olHfkWYf4R@zafu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, In the quest for BTRFS and performance, and having received the advice to "chattr +C" my akonadi DB directory to make it noCow, I would like to be sure about what will happen when I take a snapshot of the concerned BTRFS subvolume. 1/ Being noCow, will the database be modified in the snapshot as well, efectively defeating the snapshot ? 2/ Being snapshotted, will the database be COWed even though it's supposed to be noCow ? 3/ Are both options mutually incompatible in some more osbcure ways ? I'd like to know where I'm going with this ;-) TIA and kind regards. -- Swâmi Petaramesh http://petaramesh.org PGP 9076E32E