From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from datenkhaos.de ([81.89.99.198]:42715 "EHLO datenkhaos.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755254AbaDGM0P convert rfc822-to-8bit (ORCPT ); Mon, 7 Apr 2014 08:26:15 -0400 Date: Mon, 7 Apr 2014 14:18:41 +0200 From: Johannes Hirte To: Austin S Hemmelgarn Cc: =?ISO-8859-1?B?U3fibWk=?= Petaramesh , linux-btrfs@vger.kernel.org Subject: Re: BTRFS setup advice for laptop performance ? Message-ID: <20140407141841.476f8aae@datenkhaos.de> In-Reply-To: <533EA686.5030909@gmail.com> References: <2692878.dRG1K49eOP@fnix> <533EA686.5030909@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, 04 Apr 2014 08:33:10 -0400 Austin S Hemmelgarn wrote: > On 2014-04-04 04:02, Swâmi Petaramesh wrote: > > - Is it still recommended to mkfs with a nodesize or leafsize > > different (bigger) than the default ? I wouldn't like to lose too > > much disk space anyway (1/2 nodesize per file on average ?), as it > > will be limited... > This depends on many things, the average size of the files on the disk > is the biggest factor. In general you should get the best disk > utilization by setting nodesize so that a majority of the files are > less than the leafsize minus 256 bytes, and all but a few are smaller > than two times the leafsize minus 256 bytes. However, if you want to > really benefit from the data compression, you should just use the > smallest leaf/nodesize for your system (which is what mkfs defaults > to), as data that gets as BTRFS stores files whose size is at least > (roughly) 256 bytes less than the leafsize inline with the metadata, > and doesn't compress such files. With commit c652e4efb8e2dd76ef1627d8cd649c6af5905902 the default node-/leafsize has changed: commit c652e4efb8e2dd76ef1627d8cd649c6af5905902 Author: Chris Mason Date: Fri Nov 8 13:51:52 2013 -0500 mkfs: change default metadata blocksize to 16KB