From: Jan Engelhardt Subject: Re: mkfs.ext4: high default -i value undocumented Date: Wed, 4 Mar 2009 04:11:26 +0100 (CET) Message-ID: References: <49ADBB03.9070303@redhat.com> <20090304024904.GK32284@mit.edu> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Eric Sandeen , linux-ext4@vger.kernel.org, kzak@redhat.com To: Theodore Tso Return-path: Received: from sovereign.computergmbh.de ([85.214.69.204]:58558 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751916AbZCDDLa (ORCPT ); Tue, 3 Mar 2009 22:11:30 -0500 In-Reply-To: <20090304024904.GK32284@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wednesday 2009-03-04 03:49, Theodore Tso wrote: >On Wed, Mar 04, 2009 at 01:36:44AM +0100, Jan Engelhardt wrote: >> >> >> >> Creating an ext4 filesystem on a 4 GB image file (to be loop-mounted >> >> later) gives me 256K inodes. Choosing -i 4096 instead gives 1M, which >> >> would mean the default for -i is 16384. >> > >> >Which part of a 16384-data-bytes-to-inode-count ratio do you find >> >unreasonable? Do you find it unreasonably high, or unreasonably low? >> >> I think it's a bit too high, causing the amount of usable inodes >> to be a bit too low. > >So out of curiosity, what are you storing on the filesystem such that >you're worried about running out of inodes? The assumption was that >on most filesystems the average file size would indeed be bigger than >4k these days, although obviously things will vary depending on what >you plan to store. Even if you're using maildir stores, or squid >caches, it seemed like 16k was a good default. The source and module_prepare'd obj dirs for the trees 2.6.{17.14,18.8,19.7,20.21,21.7,22.19,23.17,24.7,25.20,26.8,27.8,28}. Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/loop0 xfs 4184064 3676644 507420 88% /lo/kernel Filesystem Type Inodes IUsed IFree IUse% Mounted on /dev/loop0 xfs 2343280 313466 2029814 14% /lo/kernel