[Bug 413345] Re: incorrectly assumes /dev/mapper/ -> LVM

[Marcus Tomlinson]

This release of Ubuntu is no longer receiving maintenance updates. If
this is still an issue on a maintained version of Ubuntu please let us
know.

** Changed in: grub2 (Ubuntu)
       Status: Triaged => Incomplete

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Title:
  incorrectly assumes /dev/mapper/ -> LVM

Status in grub2 package in Ubuntu:
  Incomplete
Status in os-prober package in Ubuntu:
  Invalid

Bug description:
  After installing GRUB2/Ubuntu 9.10 on a LUKS encrypted partition
  (using the alternate CD), I can no longer boot into my other
  partition.

  I have a computer with one drive and multiple partitions. To simplify
  the drive layout it I have included the following attempt at a
  diagram/explanation:

  ==
  /dev/sda1 [ /boot ]
  /dev/sda2 [ Extended container START
  -- /dev/sda8 [ / - Ubuntu 9.04]
  -- /dev/sda9  [ blank ]
  -- /dev/sda10 [ swap ]
  /dev/sda2   Extended container STOP]
  ==

  As you can see, I have a separate /boot partition which holds GRUB and
  the various kernel images (initrd/vmlinuz). As long as I was using
  GRUB 0.97-29, I did not have any problems.

  Now this is what I did to mess it up:

  1) I booted from the Ubuntu 9.10 Alpha alternate (text-install) CD

  2) Using the debian system installer, I set up /dev/sda9 to be LVM-
  over-encrypted_volume. This device will be mounted to /

  3) Using the debian system installer, I set up /dev/sda10 to be LVM-
  over-encrypted_volume. This device will be used as encrypted swap

  4) I selected the existing /dev/sda1 ( /boot ) to be mounted as /boot.

  5) Once the devices set up, the installer started by installing GRUB.
  It detected that a legacy GRUB was on /dev/sda1 and asked me if I
  wanted to write over it with GRUB2 (1.96). A dialog with an empty line
  (which should have a command in it) showed up. The dialog presented
  the following message:

  ==
  [!] Configuring grub-pc
  The following linux command line was extracted from the kopt parameter in GRUB Legacy's menu.lst. Please verify that is is correct and modify it if necessary.

  [                                                  ]
  <Go Back>         <Continue>
  ==

  Afterwards, the installation went through, and I was able to reboot
  into my new Ubuntu 9.10 alpha installation. The problem happened when
  I rebooted and attempted to go into my old 9.04 installation on
  /dev/sda1. It seems that when GRUB2 generated grub.cfg from the legacy
  menu.lst, it did not copy UUID information properly into the new
  syntax. The GRUB legacy script assumes that because I set up a LVM,
  that now all devices are on the LVM managed, when I don't think that
  they are.

  The layout after the Ubuntu 9.10 alpha installation looks like this:

  ==
  /dev/sda1 [ /boot ]
  /dev/sda2 [ Extended container START
  -- /dev/sda8 [ / - Ubuntu 9.04]
  -- /dev/sda9  [ crypt-luks ]
  --- /dev/mapper/cryptdisk-karmic
  -- /dev/sda10 [ crypt-luks ]
  --- /dev/mapper/sda10_crypt
  /dev/sda2   Extended container STOP]
  ==

  I cannot boot into Ubuntu 9.04 which is the problem I would like to
  resolve. When I select a kernel from Ubuntu 9.04, I just get a
  blinking underscore in the top left corner. Here is a line from the
  backed up legacy menu.lst followed by that same line in the new
  grub.cfg after being imported:

  menu.lst
  ==
  title		Ubuntu 9.04, kernel 2.6.28-13-generic
  uuid		1768a7ec-e0ce-8fa4-814b-2e628de7c2b2
  kernel		/vmlinuz-2.6.28-13-generic root=UUID=e1b20064-8204-4150-be5e-83bd537defc8 ro quiet splash vga=773 
  initrd		/initrd.img-2.6.28-13-generic
  quiet
  ==

  
  grub.cfg
  ==
  menuentry "Ubuntu, Linux 2.6.28-13-generic" {
  	set root=(hd0,1)
  	search --no-floppy --fs-uuid --set 1768a7ec-e0ce-8fa4-814b-2e628de7c2b2
  	linux	/vmlinuz-2.6.28-13-generic root=/dev/mapper/cryptdisk-karmic ro   quiet splash
  	initrd	/initrd.img-2.6.28-13-generic
  }
  ==

  This bug was created so that hopefully, the detection and generation
  of grub.cfg from legacy menu.lst does not mess up like this. Help to
  allow me to boot into 9.04 would also be appreciated. I hope that I
  have provide enough information to diagnose the issue.

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