From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Steigerwald Subject: Re: Partitions: Amiga RDB partition on 2 TB disk way too big, while OK in AmigaOS 4.1 Date: Sun, 17 Jun 2012 10:33:51 +0200 Message-ID: <201206171033.51625.Martin@lichtvoll.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mondschein.lichtvoll.de ([194.150.191.11]:42970 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752955Ab2FQIdx convert rfc822-to-8bit (ORCPT ); Sun, 17 Jun 2012 04:33:53 -0400 Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: linux-m68k@vger.kernel.org, Jens Axboe Sorry, forgot to keep Cc. I think I will keep the disk as is for a while. I just won=C2=B4t plug = it to the Amiga, since I have my Amiga backup on another dedicated disk and do not want to overwrite my Linux backups. So its available for testing for a while. It should be save as long as I use the disk in Linux only. =46or safety I will recreate all backups. I can checksum the BTRFS base= d backup partition for checksum errors, but fscking the other non BTRFS ones will only give a vague hint. Am Sonntag, 17. Juni 2012 schrieb Martin Steigerwald: > Hi Jens, hi Linux m68k developers, >=20 > I reported that as >=20 > https://bugzilla.kernel.org/show_bug.cgi?id=3D43511 >=20 > I will attach there some more debug data like binary copy of RDB and > such. >=20 > But maybe its easier to discuss here. I think this one is pretty serious: merkaba:~> pvdisplay /dev/sdb1 --- Physical volume --- PV Name /dev/sdb1 VG Name steigerwald PV Size 1,82 TiB / not usable 4,08 MiB Allocatable yes=20 PE Size 4,00 MiB Total PE 476931 Free PE 105731 Allocated PE 371200 PV UUID ZXMECC-JAir-lX8Q-rLhS-W1cS-quwz-b3FXWp =20 merkaba:~> vgdisplay steigerwald --- Volume group --- VG Name steigerwald System ID =20 Format lvm2 Metadata Areas 2 Metadata Sequence No 7 VG Access read/write VG Status resizable MAX LV 0 Cur LV 5 Open LV 1 Max PV 0 Cur PV 1 Act PV 1 VG Size 1,82 TiB PE Size 4,00 MiB Total PE 476931 Alloc PE / Size 371200 / 1,42 TiB Free PE / Size 105731 / 413,01 GiB VG UUID uhjjE1-0yrD-Ch1A-d9qL-P5jY-UDXE-io4bpi with merkaba:~#1> amiga-fdisk -l /dev/sdc Disk /dev/sdc: 3 heads, 16 sectors, 81396441 cylinders, RDB: 0 Logical Cylinders from 43 to 81396440, 24576 bytes/Cylinder=20 Device Boot Mount Begin End Size Pri BBlks System /dev/sdc1 * 43 65536043 1572864024 0 0 Linux= =20 native /dev/sdc2 * 65536044 78643244 314572824 0 0 =20 [unknown] /dev/sdc3 * 78643245 81396440 66076704 0 0 Amiga= =20 =46FS Int. Due to truncating oversized partition instead of refusing to use them the PV and consequently VG span the whole disk instead of leaving space for the >350GB in the two other partitions: merkaba:~> cat /proc/partitions=20 major minor #blocks name [=E2=80=A6] 8 16 1953514584 sdb 8 17 1953513552 sdb1 (now sdb instead of sdc back when I run amiga-fdisk) This is just asking for trouble. Thus: Bug 43521 - Amiga RDB partitions: truncates miscaluted partitions size=20 instead of refusing to use it https://bugzilla.kernel.org/show_bug.cgi?id=3D43521 My suggestion is to bail out if a partition size looks insane and=20 impossible. Having to manually fix it up to access the data on disk still looks bet= ter to me than potentially overwriting lots of data. Until today I never actually did an Amiga backup to the disk, I just created the two Amiga partitions and copied some screenshots of them but that might be enough to explain the checksum errors I found in a BTRFS backup partition. I am now checking my Linux backups. They might be save, cause not all space on the volume group is used. See: kernel got struck while scrubbing BTRFS with node- and leafsize 32768 http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg17108.html s/struck/stuck Thanks, --=20 Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7