From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from syrinx.knorrie.org ([82.94.188.77]:49164 "EHLO syrinx.knorrie.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1038476AbdDULNQ (ORCPT ); Fri, 21 Apr 2017 07:13:16 -0400 Received: from [IPv6:2001:828:13c8:10b::c] (blackbox.bofh.hq.mendix.net [IPv6:2001:828:13c8:10b::c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by syrinx.knorrie.org (Postfix) with ESMTPSA id D69706004A for ; Fri, 21 Apr 2017 13:13:13 +0200 (CEST) Subject: Re: Experiences with metadata balance/convert To: "linux-btrfs@vger.kernel.org" References: <78d61749-ec9c-1cc3-196f-5330489e2b3e@mendix.com> From: Hans van Kranenburg Message-ID: <6054483d-437f-e8d2-f74b-7560c9e0819d@mendix.com> Date: Fri, 21 Apr 2017 13:13:13 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 04/21/2017 12:31 PM, Hans van Kranenburg wrote: > Doh, > > On 04/21/2017 12:26 PM, Hans van Kranenburg wrote: >> [...] >> >> == Thinking out of the box == >> >> Technically, converting from DUP to single could also mean: >> * Flipping one bit in the block group type flags to 0 for each block >> group item >> * Flipping one bit in the chunk type flags and removing 1 stripe struct >> for each metadata chunk item >> * Removing the > > Removing the dev extent objects for all removed stripes from the dev tree. > >> * Anything else? >> >> How feasible would it be to write btrfs-progs style conversion to do this? >>From the feedback on IRC already, to clear things up: I'm *not* proposing/asking for this kind of functionality to be officially available or added to mainline btrfs-progs and be supported for every user to use. I understand that's a whole different kind of discussion. I only mean... would there be any great show-stopper for this idea which would mean I couldn't technically do it myself in a 'one-off' style. -- Hans van Kranenburg