From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757143AbZEEW1B (ORCPT ); Tue, 5 May 2009 18:27:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754316AbZEEW0v (ORCPT ); Tue, 5 May 2009 18:26:51 -0400 Received: from cantor.suse.de ([195.135.220.2]:52689 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754086AbZEEW0u (ORCPT ); Tue, 5 May 2009 18:26:50 -0400 From: Neil Brown To: Lars Marowsky-Bree Date: Wed, 6 May 2009 08:26:47 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18944.48423.172087.449619@notabene.brown> Cc: Lars Ellenberg , 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 In-Reply-To: message from Lars Marowsky-Bree on Tuesday May 5 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> <20090505174831.GD14192@suse.de> X-Mailer: VM 7.19 under Emacs 21.4.1 X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9D X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday May 5, lmb@suse.de wrote: > 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 cannot imagine that there would be any. Given its history, its popularity, and its modularity, there can be no question about merging it, and only a possible question on whether it should spend some time in 'staging' first. I doubt there is much call for that, but nor it is clear to be how the decision would be made. > > 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? This is lkml - no one can catch everything :-) I big part of why I was comparing and contrasting DRBD to md is because that enables me to understand it better. That sort of in-depth understanding is, for me, a prerequisite for an in-depth review. So it is all just part of the review process.... NeilBrown