From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756820AbZEERtR (ORCPT ); Tue, 5 May 2009 13:49:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752775AbZEERtA (ORCPT ); Tue, 5 May 2009 13:49:00 -0400 Received: from gate.in-addr.de ([212.8.193.158]:54616 "EHLO mx.in-addr.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751456AbZEERtA (ORCPT ); Tue, 5 May 2009 13:49:00 -0400 Date: Tue, 5 May 2009 19:48:31 +0200 From: Lars Marowsky-Bree To: Neil Brown , Lars Ellenberg Cc: James Bottomley , Philipp Reisner , linux-kernel@vger.kernel.org, Jens Axboe , Greg KH , Sam Ravnborg , Dave Jones , Nikanth Karthikesan , "Nicholas A. Bellinger" , Kyle Moffett , Bart Van Assche Subject: Re: [PATCH 04/16] DRBD: bitmap Message-ID: <20090505174831.GD14192@suse.de> References: <1241090812-13516-1-git-send-email-philipp.reisner@linbit.com> <1241090812-13516-2-git-send-email-philipp.reisner@linbit.com> <1241090812-13516-3-git-send-email-philipp.reisner@linbit.com> <1241090812-13516-4-git-send-email-philipp.reisner@linbit.com> <1241090812-13516-5-git-send-email-philipp.reisner@linbit.com> <1241278918.3639.46.camel@mulgrave.int.hansenpartnership.com> <20090502172838.GC6466@racke> <18941.10725.335758.894491@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <18941.10725.335758.894491@notabene.brown> X-Ctuhulu: HASTUR User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2009-05-03T15:21:41, Neil Brown wrote: > As I said, I don't immediately see the benefits of the activity log > format, however, > 1/ I am happy to listen to its benefits being explained > 2/ If we were to agree that merging DRBD functionality into md > (for which there isn't a concrete proposal, but the suggestion > seems to be floating around) were a good thing, I don't have any > problem with supporting an activity log in md in the name of > compatibility. So, let's take a step back here. All of this is extremely beneficial discussion to be had. As some of you are (painfully, sometimes ;-) aware, I'm a big fan of converging RAID implementations/back-ends, and the goal is well received. But this will take a while, and both drbd, md, md/nbd, or even dm-raid1 have large existing user bases, and HA environments don't switch easily. All are actively maintained. Sharing more and more of the code strikes me as a mid-term goal, and full converges as a long-term one (alas). What I think this argument has shown that drbd's design is sound (even if some choices, like that of the alternatives, are up for discussion), similar to different file systems (of which we seem to have plenty too). I would suggest at this time, we may want to refocus on the remaining objections to merging drbd as a driver in the short-term. I think I've not read anything in the last 3-5 days which still would rate as a reason for rejection or delay. Did I miss something? Regards, Lars -- SuSE Labs, OPS Engineering, Novell, Inc. SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg) "Experience is the name everyone gives to their mistakes." -- Oscar Wilde