From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Gabeler-Lee Subject: Re: Bug#597563: grub-common: grub-probe segfaults scanning lvm devices Date: Sat, 08 Jan 2011 22:09:08 -0500 Message-ID: <4D2926D4.7010300@fastcat.org> References: <20100920202854.27101.8288.reportbug@cheetah.fastcat.org> <4D274FF9.8010004@gmail.com> <4D285B79.9040100@gmail.com> <4D28F48C.1030806@gmail.com> <4D28F58F.7000401@fastcat.org> <4D28F95F.4090509@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4D28F95F.4090509@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: =?UTF-8?B?VmxhZGltaXIgJ8+GLWNvZGVyL3BoY29kZXInIFNlcmJpbmVua28=?= Cc: 597563@bugs.debian.org, linux-raid@vger.kernel.org List-Id: linux-raid.ids On 1/8/2011 18:55, Vladimir '=CF=86-coder/phcoder' Serbinenko wrote: > I have a hypothesis. Does last partition on any device span, s.t. it > leaves less than 64K after it until the end of device? If so then GRU= B > sees the same metadata sector as the one at the end of device and as = at > the end of partition. With 1.x metadata sector contains its own locat= ion > on the device. With 0.90 I can see no such field. Is there a way to > check for such condition with 0.90? I created the last partition on each disk running as close to the end o= f the=20 disk as fdisk would allow. Since the partitions were created on cylind= er=20 boundaries, however, it looks like the last partition ends 2MB before t= he=20 end of the physical device. Reading the data between the end of the la= st=20 partition and the end of the disk gives all zeros for three of the four= =20 disks, but /dev/sdb gives what looks like it might have an mdraid super= block=20 in it: $ sudo fdisk -lu /dev/sdb Disk /dev/sdb: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors Units =3D sectors of 1 * 512 =3D 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x994d834b Device Boot Start End Blocks Id System /dev/sdb1 * 63 4016249 2008093+ fd Linux raid auto= detect /dev/sdb2 4016250 8032499 2008125 fd Linux raid auto= detect /dev/sdb3 8032500 1465144064 728555782+ fd Linux raid auto= detect $ sudo dd if=3D/dev/sdb bs=3D512 skip=3D1465144064 2>/dev/null | hd 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 00260000 fc 4e 2b a9 00 00 00 00 5a 00 00 00 03 00 00 00 |.N+.....Z.= =2E.....| 00260010 00 00 00 00 a2 f7 64 93 e8 36 28 44 01 00 00 00 |......d..6= (D....| 00260020 80 f3 0e 00 03 00 00 00 02 00 00 00 00 00 00 00 |..........= =2E.....| 00260030 00 00 00 00 d5 95 46 d7 a0 b3 8d 7d 48 9e 5f 3b |......F...= =2E}H._;| 00260040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 00260080 6f 90 65 49 01 00 00 00 02 00 00 00 03 00 00 00 |o.eI......= =2E.....| 00260090 00 00 00 00 01 00 00 00 eb 34 81 5b 52 25 90 00 |.........4= =2E[R%..| 002600a0 00 00 00 00 52 25 90 00 00 00 00 00 ff ff ff ff |....R%....= =2E.....| 002600b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 00260200 00 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 |..........= =2E.....| 00260210 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| 00260220 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 00260280 01 00 00 00 08 00 00 00 11 00 00 00 01 00 00 00 |..........= =2E.....| 00260290 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| 002602a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 00260300 02 00 00 00 08 00 00 00 30 00 00 00 02 00 00 00 |........0.= =2E.....| 00260310 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 00260f80 02 00 00 00 08 00 00 00 30 00 00 00 02 00 00 00 |........0.= =2E.....| 00260f90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..........= =2E.....| * 0027e000 mdadm seems to confirm this. mdadm --examine /dev/sd[acd] gives "no md= =20 superblock", but on /dev/sdb, I get this (note that the device size at = least=20 is bogus, since the disk itself is only 750GB): $ sudo mdadm --examine /dev/sdb /dev/sdb: Magic : a92b4efc Version : 0.90.03 UUID : 9364f7a2:d74695d5:7d8db3a0:3b5f9e48 Creation Time : Mon Mar 27 14:03:04 2006 Raid Level : raid1 Used Dev Size : 979840 (957.04 MiB 1003.36 MB) Array Size : 979840 (957.04 MiB 1003.36 MB) Raid Devices : 2 Total Devices : 3 Preferred Minor : 0 Update Time : Thu Jan 8 00:34:39 2009 State : clean Active Devices : 2 Working Devices : 3 Failed Devices : 0 Spare Devices : 1 Checksum : 5b8134eb - correct Events : 9446738 Number Major Minor RaidDevice State this 2 8 48 2 spare /dev/sdd 0 0 8 1 0 active sync /dev/sda1 1 1 8 17 1 active sync /dev/sdb1 2 2 8 48 2 spare /dev/sdd --=20 -Matt "Reality is that which, when you stop believing in it, doesn't go away"= =2E -- Philip K. Dick GPG pubkey fingerprint: A57F B354 FD30 A502 795B 9637 3EF1 3F22 A85E 2A= D1 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html