[Bug 1491894] Re: lucid to precise to trusty upgrade may leave system unbootable

[Louis Bouchard]

Well, it looks like the culprit could pretty well  be a wrong setting of
the grub-pc/install_devices_empty variable.

Checking each context I find :

Lucid (initial)             : grub-pc/install_devices_empty: true
Lucid (post reconf) : grub-pc/install_devices_empty: true

Whereas on a frech Precise install we have :
* grub-pc/install_devices: /dev/vda
   grub-pc/install_devices_empty: false

When upgrading from Lucid, the debconf values are wrong since even if
grub has been installed, the debconf values do not reflect this so the
first stage is not reinstalled, hence the failed boot.

-- 
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/1491894

Title:
  lucid to precise to trusty upgrade may leave system unbootable

Status in grub2 package in Ubuntu:
  Confirmed

Bug description:
  A system, initially installed on 10.04 Lucid then upgraded to 12.04
  precise, when upgraded to Trusty may not reboot following the end of
  the do-release-upgrade command.

  Reproduction steps
  ==================

  Install a VM with 10.04.4-server ISO. When booted in 10.04, issue :

  $ sudo do-release-upgrade           # to 12.04 precise

  Then let the system upgrade and reboot.

  $ sudo do-release-upgrade           # to 14.04 trusty

  Then let the system upgrade and reboot

  Upon reboot, the system will display a blank screen with a prompt and
  will not reboot.

  Workaround
  ==========

  Force a reconfiguration of the grub-pc package :
  $ sudo dpkg-reconfigure grub-pc

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1491894/+subscriptions