[Bug 452350] Re: Unknown LVM metadata header

Thu Nov 3 20:22:27 UTC 2011

I don’t believe there’s any bug with GRUB here. In my case, I found
“leftover” PV headers on /dev/sda1 and /dev/sdb1 at offset 0x200 (sector
1). I suspect that these were created in a similar way to what Mike
Hobbs experienced in
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/452350 . I saw this
with the 11.10 Alternate installer; I didn’t like the what “auto” did
but I guess by the time I switched to “manual,” the PV headers had been
written. In my current installation, /dev/sda1 and /dev/sdb1 are in a
RAID mirror set that shows up at /dev/md0, which is used as an LVM PV.

The PV headers at /dev/sda1 and /dev/sdb1 offset 0x200
(grub_lvm_label_header with "LABELONE" magic) referenced metadata
expected at offset 0x1000, but because /dev/sda1 and /dev/sdb1 are RAID
members and version 1.2, the RAID superblock (grub_raid_super_1x or
<linux/raid/md_p.h> mdp_superblock_1 with MD_SB_MAGIC magic) was written
at that offset. This doesn’t match the LVM MD metadata, which would be
grub_lvm_mda_header with GRUB_LVM_FMTT_MAGIC magic.

GRUB was correct to issue the “unknown LVM metadata header” error
because it did find an LVM label pointing to something other than LVM
metadata. The problem was that the LVM label didn’t belong there at all.

In my case, I was able to remove the label by brute force (although I
wouldn’t recommend doing this) by running dd if=/dev/zero of=/dev/sda1
bs=512 count=2, and repeating for /dev/sdb1.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to grub2 in Ubuntu.
https://bugs.launchpad.net/bugs/452350

Title:
  Unknown LVM metadata header

Status in “grub2” package in Ubuntu:
  Confirmed
Status in “grub2” package in Debian:
  Confirmed

Bug description:
  Binary package hint: grub2

  update-grub2 appears to run successfully, but generates a lot of
  "error: Unknown LVM metadata header" messages in the process. LVM was
  created during install on a clean system (using ubuntu-9.10-beta-
  alternate-i386.iso).

  $ sudo update-grub2
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  Generating grub.cfg ...
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  Found linux image: /boot/vmlinuz-2.6.31-14-generic
  Found initrd image: /boot/initrd.img-2.6.31-14-generic
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header
  Found linux image: /boot/vmlinuz-2.6.31-11-generic
  Found initrd image: /boot/initrd.img-2.6.31-11-generic
  error: Unknown LVM metadata header
  error: Unknown LVM metadata header

  Here's some extra info that may help:

  $ mount
  /dev/mapper/root-root on / type ext4 (rw,noatime,errors=remount-ro)
  proc on /proc type proc (rw)
  none on /sys type sysfs (rw,noexec,nosuid,nodev)
  none on /sys/fs/fuse/connections type fusectl (rw)
  none on /sys/kernel/debug type debugfs (rw)
  none on /sys/kernel/security type securityfs (rw)
  udev on /dev type tmpfs (rw,mode=0755)
  none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
  none on /dev/shm type tmpfs (rw,nosuid,nodev)
  none on /var/run type tmpfs (rw,nosuid,mode=0755)
  none on /var/lock type tmpfs (rw,noexec,nosuid,nodev)
  none on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
  /dev/sda1 on /boot type ext2 (rw,noexec,nosuid,nodev,noatime)

  $ ls -la /boot
  total 26783
  drwxr-xr-x  4 root root    1024 2009-10-15 11:27 .
  drwxr-xr-x 22 root root    4096 2008-11-18 16:28 ..
  -rw-r--r--  1 root root  628340 2009-09-25 05:18 abi-2.6.31-11-generic
  -rw-r--r--  1 root root  629174 2009-10-15 01:09 abi-2.6.31-14-generic
  -rw-r--r--  1 root root  111218 2009-09-25 05:18 config-2.6.31-11-generic
  -rw-r--r--  1 root root  111371 2009-10-15 01:09 config-2.6.31-14-generic
  drwxr-xr-x  2 root root    3072 2009-10-15 11:58 grub
  -rw-r--r--  1 root root 7297493 2008-11-17 15:49 initrd.img-2.6.31-11-generic
  -rw-r--r--  1 root root 7283454 2009-10-15 11:27 initrd.img-2.6.31-14-generic
  drwxr-xr-x  2 root root   12288 2008-11-17 15:24 lost+found
  -rw-r--r--  1 root root  128796 2009-09-28 05:17 memtest86+.bin
  -rw-r--r--  1 root root 1657331 2009-09-25 05:18 System.map-2.6.31-11-generic
  -rw-r--r--  1 root root 1664737 2009-10-15 01:09 System.map-2.6.31-14-generic
  -rw-r--r--  1 root root    1196 2009-09-25 05:21 vmcoreinfo-2.6.31-11-generic
  -rw-r--r--  1 root root    1196 2009-10-15 01:12 vmcoreinfo-2.6.31-14-generic
  -rw-r--r--  1 root root 3873888 2009-09-25 05:18 vmlinuz-2.6.31-11-generic
  -rw-r--r--  1 root root 3890400 2009-10-15 01:09 vmlinuz-2.6.31-14-generic

  $ sudo sfdisk -l /dev/sda

  Disk /dev/sda: 974 cylinders, 255 heads, 63 sectors/track
  Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

     Device Boot Start     End   #cyls    #blocks   Id  System
  /dev/sda1   *      0+     30      31-    248976   83  Linux
  /dev/sda2         31     973     943    7574647+  8e  Linux LVM
  /dev/sda3          0       -       0          0    0  Empty
  /dev/sda4          0       -       0          0    0  Empty

  ProblemType: Bug
  Architecture: i386
  Date: Thu Oct 15 11:59:41 2009
  DistroRelease: Ubuntu 9.10
  Package: grub-pc 1.97~beta4-1ubuntu1
  ProcEnviron:
   LANG=C
   SHELL=/bin/bash
  ProcVersionSignature: Ubuntu 2.6.31-14.47-generic
  SourcePackage: grub2
  Uname: Linux 2.6.31-14-generic i686

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/452350/+subscriptions