From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07E70C433F5 for ; Wed, 8 Dec 2021 13:10:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234115AbhLHNNc (ORCPT ); Wed, 8 Dec 2021 08:13:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230458AbhLHNNb (ORCPT ); Wed, 8 Dec 2021 08:13:31 -0500 Received: from rin.romanrm.net (rin.romanrm.net [IPv6:2001:bc8:2dd2:1000::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E26A4C061746 for ; Wed, 8 Dec 2021 05:09:59 -0800 (PST) Received: from nvm (nvm2.home.romanrm.net [IPv6:fd39::4a:3cff:fe57:d6b5]) by rin.romanrm.net (Postfix) with SMTP id D57205F7; Wed, 8 Dec 2021 13:09:56 +0000 (UTC) Date: Wed, 8 Dec 2021 18:09:55 +0500 From: Roman Mamedov To: Rory Campbell-Lange Cc: linux-btrfs@vger.kernel.org Subject: Re: trouble replacing second disk from pair Message-ID: <20211208180955.170c6138@nvm> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, 8 Dec 2021 12:40:14 +0000 Rory Campbell-Lange wrote: > We're trying to upgrade the disks in a btrfs pair, and I have successfully replaced one of them using btrfs replace. I presently have > > Label: 'btrfs-bkp' uuid: da90602a-b98e-4f0b-959a-ce431ac0cdfa > Total devices 2 FS bytes used 700.29GiB > devid 2 size 2.73TiB used 1.73TiB path /dev/mapper/cdisk4 > devid 3 size 2.73TiB used 1.75TiB path /dev/mapper/cdisk2 > > I'd like to get rid of cdisk2 and replace it with a new disk. > > However I'm unable to mount cdisk4 (the new disk) in degraded mode to allow me to similarly replace cdisk2 as I previously did for cdisk3. Is this because some of the data in only on cdisk2? If so I'd be grateful to > know how to ensure the two disks have the same data and to allow cdisk2 to be replaced. Looks like you need to ensure everything is RAID1 first: btrfs balance start -dconvert=raid1,soft /bkp btrfs balance start -mconvert=raid1,soft /bkp btrfs balance start -sconvert=raid1,soft /bkp It might warn you about operating on system chunks, but I believe this still needs to be done. If still unable to mount after that, then post what mount command do you use and which messages you get in dmesg. -- With respect, Roman