Kubuntu 11.10 with encrypted root upgraded to 12.04 result in unbootable system due to Grub limitations
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
grub2 (Ubuntu) |
Expired
|
Undecided
|
Unassigned |
Bug Description
I have perfectly working Kubuntu 11.10 system. The machine is Dell Precision T5500 with the following disks
/dev/sda 164 GB
- dev/sda1 - primary - Windows XP
/dev/sdb 1TB
- /dev/sdb1 - primary - Windows 7 system partition
- /dev/sdb2 - primary - WIndows 7 OS
- /dev/sdb3 - primary - Kubuntu 11.10 /boot partition
- /dev/sdb4 - extended partition
- /dev/sdb5 - logical LUKS encryption partition mapped to / (root)
- /dev/sdb6 - logical LUKS encrypted partition swap
After online upgrade to 12.04 which went without any issues I rebooted the system. I was presented with GRUB menu which correctly listed
- Ubuntu 12.04 with latest 3.x server
- Previous Kernel versions
- Window 7
- Windows XP
Regardless with option I choose I receive 3 errors
- no such partition
If I drop to Grub console and I try to do ls I receive error
- no such partition
When I reboot to Ubuntu or Kubuntu alternative CD and try to do rescue
It correctly detects all my partitions, asks for passwords for /dev/sdb5 and /dev/sdb6 and unlocks them
If I try to to grub reinstall I receive error it cannot reinstall it
If I try to chroot to /dev/mapper/
If I try to do grub-install I get error that is cannot find mapping for /dev/mapper/
If I try to do grub-probe as suggested by grub-update I get error that it cannot find mapping for /dev/mapper/
If I try to run grub-devicemap it maps only /dev/sda and /dev/sdb but not /dev/mapper/
If I try to modify device.map file manually it doesn't work
If I try to do update-grub I get reference that GRUB doesn't understand LUKS encrypted volumes and look at bug http://
At the end I am unable to fix the system since grub doesn't allow me to update the boot sector to bootable system. I had to reinstall.
I have also logged it as
https:/
since it happened during upgrade but logging it also specifically against GRUB since it seems to be limitation of GRUB in 12.04 resulting in unbootable system
You need to have your /boot partition mounted to reinstall grub. Please run sudo dpkg-reconfigure grub-pc and make sure it is set to install to /dev/sda and see if this fixes it.