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=-7.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,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 7BC99C4320E for ; Thu, 26 Aug 2021 17:00:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66DC160F6F for ; Thu, 26 Aug 2021 17:00:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243158AbhHZRBj (ORCPT ); Thu, 26 Aug 2021 13:01:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243147AbhHZRBj (ORCPT ); Thu, 26 Aug 2021 13:01:39 -0400 Received: from hermes.turmel.org (hermes.turmel.org [IPv6:2604:180:f1::1e9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE539C061757 for ; Thu, 26 Aug 2021 10:00:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=turmel.org; s=a; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Sender:Reply-To:Cc:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=+a6FjJXxRh18RTOAJNwyUbcYDofVv8NZqZIrwzGq2Rs=; b=eiRGgKxmVL8krCfQ1duorLx5dm j0ni9cueLJ1Yvgw31rMPPZbwwIyXwQ3wOFrQXAQn1biJxvZw2LKHez3tnFXg46DqkPWU+oGSsuJxD fwbgeJ2RwVkc27MNlo/juT8/J5MiQ4ewjjmGCUrq59mzsMO6mMBfBY7mdkaOEgDQ9Pv9l/1qjbvhw T7yGuv3LMM3D2fD4JTBRObvm6e+LJAY09KkbQzS6JiZU9vRR19jBVY2apN71KUX53QvkRcaIkoKt7 tk2Al0CWPLe96m6O9vqmMnRo6ts8GjoIZI7Cx2OXdjAaHHWNquvhd8wq5TlYs3RAzQsmrD13X/ICt mEHP4miQ==; Received: from [12.35.44.237] (helo=[172.30.0.251]) by hermes.turmel.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mJIkC-00072J-US; Thu, 26 Aug 2021 17:00:48 +0000 Subject: Re: Raid 5 where 2 disks out of 4 were unplugged To: Gennaro Oliva , linux-raid@vger.kernel.org References: From: Phil Turmel Message-ID: <11fe0c66-c128-2217-83fc-583d1a6c2b6e@turmel.org> Date: Thu, 26 Aug 2021 13:00:48 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Hello Gennaro, Good report. On 8/26/21 5:18 AM, Gennaro Oliva wrote: > Hello, > I have a QNAP with Linux 3.4.6 and mdadm 3.3. I have 4 drives assembled > in raid 5, two of those drives where accidentally removed and now they > are out of sync. This is a partial output of mdadm --examine [trim /] > mdadm --verbose --assemble --force /dev/md1 /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3 > mdadm: looking for devices for /dev/md1 > mdadm: failed to get exclusive lock on mapfile - continue anyway... > mdadm: /dev/sda3 is identified as a member of /dev/md1, slot 0. > mdadm: /dev/sdb3 is identified as a member of /dev/md1, slot 1. > mdadm: /dev/sdc3 is identified as a member of /dev/md1, slot 2. > mdadm: /dev/sdd3 is identified as a member of /dev/md1, slot 3. > mdadm: added /dev/sdb3 to /dev/md1 as 1 > mdadm: added /dev/sdc3 to /dev/md1 as 2 (possibly out of date) > mdadm: added /dev/sdd3 to /dev/md1 as 3 (possibly out of date) > mdadm: added /dev/sda3 to /dev/md1 as 0 > mdadm: /dev/md1 assembled from 2 drives - not enough to start the array. > This should have worked. I suspect your mdadm is one of the buggy ones for forced assembly. Download and compile latest mdadm and do this again. (Newer mdadm works on older kernels.) Regards, Phil