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 X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0349C433E1 for ; Thu, 27 Aug 2020 17:14:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 334EE2087E for ; Thu, 27 Aug 2020 17:14:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=libero.it header.i=@libero.it header.b="Ge3XcsFk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726880AbgH0ROX (ORCPT ); Thu, 27 Aug 2020 13:14:23 -0400 Received: from smtp-33.italiaonline.it ([213.209.10.33]:57250 "EHLO libero.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726246AbgH0ROW (ORCPT ); Thu, 27 Aug 2020 13:14:22 -0400 Received: from venice.bhome ([94.37.192.142]) by smtp-33.iol.local with ESMTPA id BLTek4MMD8e2WBLTekTteE; Thu, 27 Aug 2020 19:14:18 +0200 x-libjamoibt: 1601 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=libero.it; s=s2014; t=1598548458; bh=+SWmZAoTUwAPsLBnIjlmEInqFPb9ns4Lc5lWAe52rDM=; h=From; b=Ge3XcsFkTFuyorgupasPnf/INNJNlTs9sfsf6DWyJFoSgQO4t3CfrLfzEEkPsn9G7 vKoB7FzWaBSuH0ks9XcAJQyGELz6fGNuC2UhZFQppxnehJYi7daFQWEyWuDCWj6TJf D8tj0fkiE0yg98r6D/H5Hm+Sz5aAEvQPSZFJeIrvrGCjBjSxm4hsRMlxytWr8K4sL+ il4u52K3Wg3utsui3pei+LXLgg+qxjfdTFvhGClb5bQ0q/NKKeOlpqf40lP8uGAwa9 BdugEFeS54N2ptFxbXixv9RnegrcabGq7oAexnTEqxjtsiyW2Fp+WU0M8qpieUtbvf 1lnygvoDXtg+Q== X-CNFS-Analysis: v=2.4 cv=ZYejiuZA c=1 sm=1 tr=0 ts=5f47e9ea a=ppQ2YIgYQAGACouVZCsPPQ==:117 a=ppQ2YIgYQAGACouVZCsPPQ==:17 a=IkcTkHD0fZMA:10 a=Oe0UhN7WJhCyF6pNc-4A:9 a=QEXdDO2ut3YA:10 Reply-To: kreijack@inwind.it Subject: Re: adding new devices to degraded raid1 To: Eric Wong , linux-btrfs@vger.kernel.org References: <20200827124147.GA16923@dcvr> From: Goffredo Baroncelli Message-ID: <862ab235-298a-12eb-647b-04ec01d95293@libero.it> Date: Thu, 27 Aug 2020 19:14:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200827124147.GA16923@dcvr> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfA+Kn/stTSPF0ICoyx7niLxauzzbq0pt4yyrVBKgIA08Phj6gQrkIbU9S7r6RUzNUY8nBZ1uks+3RQTGA4r6FXCwAGtm2IBJN/5tA+pCYJyjsMxFg79i LnnmnmoEdA/a1gimBbVHhozfPlXke3KycKsLJNGB75cfM8yttlV+3d3RpPvFnzSwaETKEPQ8Sgg+PeWxfSPHmqtkgixdm6BNwjE= Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 8/27/20 2:41 PM, Eric Wong wrote: > I don't need to do it right away, but is it possible to add new > devices to a degraded raid1? > > One thing I might do in the future is replace a broken big drive > with two small drives. It may even be used to migrate to SSDs. > > Since btrfs-replace only seems to do 1:1 replacements, and I > needed to physically remove an existing broken device to make > room for the replacements, could I do something like: > > mount -o degraded /mnt/foo > btrfs device add small1 small2 /mnt/foo > btrfs device remove broken /mnt/foo > > ? > Instead of btrfs device remove broken /mnt/foo You should do btrfs device remove missing /mnt/foo ("missing" has to be write as is, it is a special term, see man page) and btrfs balance start /mnt/foo To redistribute the data to the disks. Please before trying it, wait for other suggestions or confirmation from more expert dveloper about that BR G.Baroncelli > Anyways, so far raid1 has been working great for me, but I have > some devices nearing 70K Power_On_Hours according to SMART > > Thanks. > -- gpg @keyserver.linux.it: Goffredo Baroncelli Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5