From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030190AbWGaX34 (ORCPT ); Mon, 31 Jul 2006 19:29:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030374AbWGaX34 (ORCPT ); Mon, 31 Jul 2006 19:29:56 -0400 Received: from warden-p.diginsite.com ([208.29.163.248]:61359 "HELO warden.diginsite.com") by vger.kernel.org with SMTP id S1030190AbWGaX3z (ORCPT ); Mon, 31 Jul 2006 19:29:55 -0400 Date: Mon, 31 Jul 2006 16:27:02 -0700 (PDT) From: David Lang X-X-Sender: dlang@dlang.diginsite.com To: Nate Diller cc: Matthias Andree , Adrian Ulrich , "Horst H. von Brand" , ipso@snappymail.ca, reiser@namesys.com, lkml@lpbproductions.com, jeff@garzik.org, tytso@mit.edu, linux-kernel@vger.kernel.org, reiserfs-list@namesys.com Subject: Re: Solaris ZFS on Linux [Was: Re: the " 'official' point of view" expressed by kernelnewbies.org regarding reiser4 inclusion] In-Reply-To: <5c49b0ed0607311621i54f1c46fh9137f8955c9ea4be@mail.gmail.com> Message-ID: References: <20060731175958.1626513b.reiser4@blinkenlights.ch> <200607311918.k6VJIqTN011066@laptop13.inf.utfsm.cl> <20060731225734.ecf5eb4d.reiser4@blinkenlights.ch> <44CE7C31.5090402@gmx.de> <5c49b0ed0607311621i54f1c46fh9137f8955c9ea4be@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 31 Jul 2006, Nate Diller wrote: > > On 7/31/06, Matthias Andree wrote: >> Adrian Ulrich wrote: >> >> > See also: http://spam.workaround.ch/dull/postmark.txt >> > >> > A quick'n'dirty ZFS-vs-UFS-vs-Reiser3-vs-Reiser4-vs-Ext3 'benchmark' >> >> Whatever Postmark does, this looks pretty besides the point. > > why's that? postmark is one of the standard benchmarks... > >> Are these actual transactions with the "D"urability guarantee? >> 3000/s doesn't look too much like you're doing synchronous I/O (else >> figures around 70/s perhaps 100/s would be more adequate), and cache >> exercise is rather irrelevant for databases that manage real (=valuable) >> data... > > Data: > 204.62 megabytes read (8.53 megabytes per second) > 271.49 megabytes written (11.31 megabytes per second) > > looks pretty I/O bound to me, 11.31 MB/s isn't exactly your latest DDR > RAM bandwidth. as far as the synchronous I/O question, Reiser4 in > this case acts more like a log-based FS. That allows it to "overlap" > synchronous operations that are being submitted by multiple threads. what you are missing is that apps that need to do lots of syncing (databases, mail servers) need to wait for the data to hit non-volitile media before the write is complete. this limits such apps to ~1 write per revolution of the platters (yes it's possible for a limited time to have multiple writes to different things happen to be on the same track, but the counter is the extra seek time needed between tracks) so any benchmark that shows more transactions then the media has revolutions is highly suspect (now if you have battery-backed cache, or the equivalent you can blow past these limits) on consumer (7200 rpm) drives this limit is 120/sec, on high-end drives (15Krpm scsi's this is 250/sec, and on the 10k rpm drives in the middle it's about 166/sec. David Lang