Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 15 Jul 2002 13:45:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 15 Jul 2002 13:45:28 -0400 Received: from noc.easyspace.net ([62.254.202.67]:10003 "EHLO noc.easyspace.net") by vger.kernel.org with ESMTP id ; Mon, 15 Jul 2002 13:45:28 -0400 Date: Mon, 15 Jul 2002 18:48:05 +0100 From: Sam Vilain To: Andreas Dilger Cc: dax@gurulabs.com, linux-kernel@vger.kernel.org Subject: Re: [ANNOUNCE] Ext3 vs Reiserfs benchmarks In-Reply-To: <20020715160357.GD442@clusterfs.com> References: <1026490866.5316.41.camel@thud> <1026679245.15054.9.camel@thud> <1026736251.13885.108.camel@irongate.swansea.linux.org.uk> <20020715160357.GD442@clusterfs.com> X-Mailer: Sylpheed version 0.7.8claws (GTK+ 1.2.10; i386-debian-linux-gnu) X-Face: NErb*2NY4\th?$s.!!]_9le_WtWE'b4;dk<5ot)OW2hErS|tE6~D3errlO^fVil?{qe4Lp_m\&Ja!;>%JqlMPd27X|;b!GH'O.,NhF*)e\ln4W}kFL5c`5t'9,(~Bm_&on,0Ze"D>rFJ$Y[U""nR Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2100 Lines: 41 Andreas Dilger wrote: > Amusingly, there IS directory hashing available for ext2 and ext3, and > it is just as fast as reiserfs hashed directories. See: > http://people.nl.linux.org/~phillips/htree/paper/htree.html You learn something new every day. So, with that in mind - what has reiserfs got that ext2 doesn't? - tail merging, giving much more efficient space usage for lots of small files. - B*Tree allocation offering ``a 1/3rd reduction in internal fragmentation in return for slightly more complicated insertions and deletion algorithms'' (from the htree paper). - online resizing in the main kernel (ext2 needs a patch - http://ext2resize.sourceforge.net/). - Resizing does not require the use of `ext2prepare' run on the filesystem while unmounted to resize over arbitrary boundaries. - directory hashing in the main kernel On the flipside, ext2 over reiserfs: - support for attributes without a patch or 2.4.19-pre4+ kernel - support for filesystem quotas without a patch - there is a `dump' command (but it's useless, because it hangs when you run it on mounted filesystems - come on, who REALLY unmounts their filesystems for a nightly dump? You need a 3 way mirror to do it while guaranteeing filesystem availability...) I'd be very interested in seeing postmark results without the hierarchical directory structure (which an unpatched postfix doesn't support), with about 5000 mailboxes with and without the htree patch (or with the htree patch but without that directory indexed, if that is possible). -- Sam Vilain, sam@vilain.net WWW: http://sam.vilain.net/ 7D74 2A09 B2D3 C30F F78E GPG: http://sam.vilain.net/sam.asc 278A A425 30A9 05B5 2F13 Try to be the best of what you are, even if what you are is no good. ASHLEIGH BRILLIANT - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/