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My installation is a Ubuntu 12.04 64 bits (Classic "legacy" MBR - No EFI/UEFI here) with two partition :

  1. A separate boot partition
  2. An encrypted LUKS volume that contains the system Logical Volumes

I seems I accidentaly deleted all the current kernel files with:

sudo apt-get purge 'linux-image-3.8*'

I applied the updates with Ubuntu Software Update, rebooted and then: Ubuntu can't boot.

I tried to boot on a live DVD with a 14.04.1 Ubuntu and can still see my partitions (described later):

/dev/sda1 (boot) /dev/sda2 (Encrypted volume) /dev/sda5 (Logical Volume container)

What are the steps to recover/reinstall the kernel files and dependencies in order to cleanly reboot my installed system?

Thanks in advance

g0lem
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2 Answers2

3

Test this:

Start the computer with a live-dvd / usb.

Open a terminal.

Run it:

sudo -i
apt-get update
apt-get install lvm2 cryptsetup
modprobe dm-crypt
cryptsetup luksOpen /dev/sda2 crypt1
*##Write the passphrase##*
vgscan --mknodes
*##Save the volume name##*
mount /dev/<volume-name>/root /mnt
mount /dev/sda1 /mnt/boot
mount --bind /dev /mnt/dev 
mount --bind /dev/pts /mnt/dev/pts
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
cp /etc/resolv.conf /mnt/etc/resolv.conf
chroot /mnt
apt-get update
apt-get install --reinstall 'linux-image-3.8*'
update-grub 
apt-get clean
umount /mnt
reboot
Community
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kyodake
  • 15,401
  • Thanks for this procedure, I'm going to test it. Question: my home folder is also encrypted (with ecryptfs), is there an impact regarding your procedure? Are their some config files residing within the (encrypted) home folder needed to re-install the kernel & rebuild grub? – g0lem Sep 25 '14 at 11:27
  • Ubuntu repositories URLs aren't resolved in the chrooted environment, so apt-get can't gather informations from the Internet. I can ping internal & external IPs from the chrooted environment, but can't resolve hostnames. How can I set the name resolution? I booted from Ubuntu 14.04 DVD and the installed system I'm trying to recover is 12.04.2, does it matter? – g0lem Oct 12 '14 at 16:48
  • I wonder if copying the /etc/apt/sources.list from the chrooted environment (Ubuntu 12.04.3 Precise) to the live session (Ubuntu 14.04 trusty) /etc/apt/sources.list would get the Ubuntu repositories to be resolved correctly or mess things... I'd rather try a 12.04 DVD instead. There(s definitely a problem regarding the difference of the live session and the installed system version. – g0lem Oct 12 '14 at 17:10
  • This worked for me, combined with krm's comment below. Saved me hours of agony, thank you! – Andreas Jansson Aug 27 '17 at 12:45
1

I tried kyodake's answer above but kept getting this error after installation of the kernel: cryptsetup: WARNING: invalid line in /etc/crypt1 -. It would then reboot into an initramfs shell.

I got information from this answer that I had to unlock the encrypted volume, which was /dev/sda5 in my case, with the same name that the installed system expected.

Therefore I had to do cryptsetup luksOpen /dev/sda5 sda5_crypt for that particular step, which worked. Both the installed system and the live usb were 14.04

krm
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