From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 94988138350 for ; Thu, 30 Apr 2020 13:44:55 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id E10DCE0953; Thu, 30 Apr 2020 13:44:49 +0000 (UTC) Received: from smtpcmd10101.aruba.it (smtpcmd10101.aruba.it [62.149.156.101]) by pigeon.gentoo.org (Postfix) with ESMTP id 43A6EE08D0 for ; Thu, 30 Apr 2020 13:44:49 +0000 (UTC) Received: from mail.agr.fm ([151.48.153.140]) by smtpcmd10.ad.aruba.it with bizsmtp id Z1kn2202b320c1T011koNU; Thu, 30 Apr 2020 15:44:48 +0200 Received: from raven.agr.fm (raven.agr.fm [192.168.64.6]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.agr.fm (Postfix) with ESMTPS id C796B36001B for ; Thu, 30 Apr 2020 15:44:45 +0200 (CEST) From: Andrea Conti Subject: Re: [gentoo-user] Trouble with backup harddisks To: gentoo-user@lists.gentoo.org References: <20200430093217.efprkpt4kbvir7nr@solfire> <5EAAA0AB.3050505@youngman.org.uk> Message-ID: <22faa7cf-7291-b430-c646-b96c6d428f19@alyf.net> Date: Thu, 30 Apr 2020 15:44:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 In-Reply-To: <5EAAA0AB.3050505@youngman.org.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aruba.it; s=a1; t=1588254288; bh=nXmWHwkeX/jOLXg0UU0FnJp7Dx/l0+xGhy6DlJlHi04=; h=From:Subject:To:Date:MIME-Version:Content-Type; b=IfHD8OT+eqxCkPG7VYCx6VOU1izln9Ldd1RTf1SeQZqIurQ6R68da3o0Ldlke5hRy pejFquj0zwqNGvDGpyAtzkkiVqF7fwurz8IrxkHVbIpZABFHI/Q8656pyrehpBD5Ua 71xLOmI8ROFxaUzOhZQ+Lt78jQBMLSnbK613OVbOHy2eR1gQH8MMXk+w98vzYw7e+S S8Evlga3F3qSukHMSadDJCC8iL6WI/74q2PaxrepBWZba+U2Y7sHtwSrXmnmtiw6vP MaI5G2y81hTSMLOndUA+ZskkehOXOaU9uZArwX/5ofVXDz/oVD9q27Xtcx/laWLOhl dzFv8ognCtXrw== X-Archives-Salt: 84759d63-224f-493e-82c0-ff08e20b69d9 X-Archives-Hash: 27fd8bd3a8ae2d79bb5109c6045cb24a Hi, >> CONFIG_PARTITION_ADVANCED=y >> CONFIG_MSDOS_PARTITION=y >> CONFIG_EFI_PARTITION=y That's all you need. > This could be the key. Sector sizes have been changing from 512 to 4096 > over many years. If your kernel has been updated to expect/use 4096 byte > sectors, it might not be able to read the disk properly. Sector size is only a (fixed) property of a specific block device, not something expected or required by the kernel. Sector sizes other than 512B have been around for ages without any problems, even in consumer hardware (e.g. CDs and DVDs have 2KB sectors). > Disklabel type: dos > Device Boot Start End Sectors Size Id Type > /dev/sdb1 1 1953458175 1953458175 931.5G ee GPT That looks... broken. fdisk is recognizing the disk as MBR (a GPT disk would have "Disklabel type: gpt"), but the partition table is a protective MBR, which makes no sense in a non-GPT disk. My guess is that this disk was at some time partitioned with GPT (possibly it came that way from WD?), but then it was only used in machines with no kernel support for GPT. Such a machine will happily treat that as a normal MBR and allow you to access the protective entry as a normal partition, which means you can create a filesystem on it and fill it with data, destroying the GPT structures. A GPT-aware kernel on the other hand will recognize that as a protective MBR and it will ignore it --but since the disk does not contain any valid GPT structures, it will not show any partitions. Try running "gdisk -l /dev/sdb"; for a valid GPT disk it will say: Partition table scan: MBR: protective BSD: not present APM: not present GPT: present If that's not the case and you have no GPT, you will have to fix things manually. Since the disk is only 1TB, there is no reason to use GPT at all, so your best bet is to use fdisk to make that a standard MBR by changing the partition type from 'ee' to '83'. andrea