From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net ([212.227.15.18]:55862 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751940AbbLETig (ORCPT ); Sat, 5 Dec 2015 14:38:36 -0500 Received: from guidonb ([79.194.183.215]) by mail.gmx.com (mrgmx002) with ESMTPSA (Nemesis) id 0LkgEO-1afjPa35Qy-00aSrW for ; Sat, 05 Dec 2015 20:38:34 +0100 From: To: "'linux-btrfs'" References: <4082684905f25f921ae4564b1c8a892e@admin.virtall.com> In-Reply-To: <4082684905f25f921ae4564b1c8a892e@admin.virtall.com> Subject: RE: compression disk space saving - what are your results? Date: Sat, 5 Dec 2015 20:38:34 +0100 Message-ID: <011f01d12f94$88412110$98c36330$@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-btrfs-owner@vger.kernel.org List-ID: > Subject: compression disk space saving - what are your results? > > What are your disk space savings when using btrfs with compression? I checked that for some folders when I moved from ext4 to btrfs. I compared du with df** just to get some numbers. I use lzo since btrfs-wiki said its better for speed. Percent_saving=(1-df/du)*100: 47% (mostly endless text files, source code etc., total amount of data is about 1TB) 2%-10% (for data which is mostly in the form of large (several hundred MB up to fewGB) binary files, total amount is about 4TB) 23% (for something in between, total amount is 0.4TB) Result indicate pretty clearly: large binary files are almost not compressed - without understanding much of it that's what I would intuitively expect (afaik lzo is dictionary based and those binary files have little for that). ** du -s on the folder I copied to the btrfs drive. df is the difference in between a df before and after the copy. Based on casual checking results were consistent with the space needed on the old ext4 drive.