From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 3264A13877A for ; Mon, 7 Jul 2014 12:46:59 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 7B4FCE08CD; Mon, 7 Jul 2014 12:46:54 +0000 (UTC) Received: from postler.lichtfels.com (postler.lichtfels.com [78.46.92.195]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 6606EE07D2 for ; Mon, 7 Jul 2014 12:46:52 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by postler.lichtfels.com (Postfix) with ESMTP id 357B4125D0 for ; Mon, 7 Jul 2014 14:46:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xunil.at; s=mailout; t=1404737211; bh=oMs8tsl65oRk98QuYF+GlzoLpKJGHo1GjscUZOqasPM=; h=Date:From:Reply-To:To:Subject:References:In-Reply-To; b=l2p/FEGWhj2KKtHC1q9HOqrURm14kFhSDw5Or4Wwfjr3cSCpM8YS2tSQ0PTw7jMnD Kg1+BCzUzk3XmrvBJzQy3kVWqLmEPFLuPBv+uAkz4IR5OK+YhWwE2KBJCtc6KDKaCD uMlvZS6jAWh4LJ6BjDvOMM8++9sAUwE6J6Kh65ik= Received: from postler.lichtfels.com ([127.0.0.1]) by localhost (postler.lichtfels.com [127.0.0.1]) (amavisd-maia, port 10024) with LMTP id 18218-08 for ; Mon, 7 Jul 2014 14:46:49 +0200 (CEST) Received: from [IPv6:2001:15c0:65ff:8742:6c02:afb4:829f:3a2e] (unknown [IPv6:2001:15c0:65ff:8742:6c02:afb4:829f:3a2e]) (using TLSv1 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by postler.lichtfels.com (Postfix) with ESMTPSA id 37B48123CA for ; Mon, 7 Jul 2014 14:46:49 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xunil.at; s=mailout; t=1404737209; bh=oMs8tsl65oRk98QuYF+GlzoLpKJGHo1GjscUZOqasPM=; h=Date:From:Reply-To:To:Subject:References:In-Reply-To; b=hzRCPOt0NzahKF5lKswbHsZoxsuaM9gKL8L2CsghTgRYr96h65UoKZwdTcT703laR c9oWJJ2Lty4BeUGYY75xWwvE1hkRCD1CYmwF7UO+xrl8Zof6xNWcAViaqP7FMXtMdo OMZAAMVL++O3BMAcanmP17bTsVftQRSRzbxic5zs= Message-ID: <53BA96B8.2000303@xunil.at> Date: Mon, 07 Jul 2014 14:46:48 +0200 From: "Stefan G. Weichinger" Organization: oops! User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] btrfs: subvol without compression References: <53A020A8.2070809@xunil.at> <20140620120700.73303d6c@marcec> In-Reply-To: <20140620120700.73303d6c@marcec> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.2c X-Archives-Salt: 94fa5598-d799-48b7-bd0a-df2a3788ac16 X-Archives-Hash: cfbb983f030ccf8faf5fb2427e64dd33 Am 20.06.2014 12:07, schrieb Marc Joliet: > From my own google search, at least up to 2011 per-subvolume > compression settings were not possible. Then, after subsequently > searching on the btrfs wiki for a while, I finally found an answer: > no. See this FAQ entry: > > https://btrfs.wiki.kernel.org/index.php/FAQ#Can_I_mount_subvolumes_with_different_mount_options.3F > > [...] This seems to be the same for the option nodatacow. I wanted to test this with VM-images in a separate subvolume, and with this script: https://github.com/stsquad/scripts/blob/master/uncow.py It was mentioned here: https://btrfs.wiki.kernel.org/index.php/FAQ#Can_copy-on-write_be_turned_off_for_data_blocks.3F Does somebody already have experience with turning off COW for specific files like VM images? I would like to take 2 demo VMs with me on my thinkpad, and there I don't have that much flexibility to add another hdd w/ ext4 or something. As far as I have seen so far, for demoing the performance isn't too bad anyway. Stefan