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 92D2EC7619A for ; Tue, 11 Apr 2023 18:20:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229704AbjDKSUw (ORCPT ); Tue, 11 Apr 2023 14:20:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229807AbjDKSUu (ORCPT ); Tue, 11 Apr 2023 14:20:50 -0400 X-Greylist: delayed 505 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 11 Apr 2023 11:20:48 PDT Received: from itrosinen.de (itrosinen.de [185.13.148.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13B515B92 for ; Tue, 11 Apr 2023 11:20:47 -0700 (PDT) Received: from localhost (localhost.localdomain [127.0.0.1]) by itrosinen.de (Postfix) with ESMTP id 428AF4E5E7 for ; Tue, 11 Apr 2023 20:12:22 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at itrosinen.de Received: from itrosinen.de ([127.0.0.1]) by localhost (itrosinen.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hDEUJi69LKNY for ; Tue, 11 Apr 2023 20:12:21 +0200 (CEST) Received: from www.itrosinen.de (unknown [172.17.0.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: moritz) by itrosinen.de (Postfix) with ESMTPSA id E2BEA4E5E6 for ; Tue, 11 Apr 2023 20:12:21 +0200 (CEST) MIME-Version: 1.0 Date: Tue, 11 Apr 2023 20:12:21 +0200 From: Moritz Rosin To: linux-raid@vger.kernel.org Subject: Recover data from accidentally created raid5 over raid1 Message-ID: <432ab0ccdb077378295ceedb82ac162f@itrosinen.de> X-Sender: moritz@itrosinen.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Hey there, unfortunately I have to admit, that I learned my lesson the hard way dealing with software raids. I had a raid1 running reliable over month using two 4TB HDDs. Since I ran short on free space I tried to convert the raid1 to a raid5 in-place (with the plan to add the 3rd HDD after converting). That's where my incredibly stupid mistake kicked in. I followed an internet tutorial that told me to do: mdadm --create /dev/md0 --level=5 --raid-devices=2 /dev/sdX1 /dev/sdY1 I learned that I re-created a raid5 array instead of converting the raid1 :-( Is there any chance to un-do the conversion or restore the data? Has the process of creation really overwritten data or is there anythins left on the disk itself that can be rescued? Any help would be appreciated. Thanks!!! Moritz