Ubuntu 12.10 32-bit on LVM partition fails to boot

[Gabor Dicso]

Hi All,

my Ubuntu 12.10 32-bit does not boot. Looks like my LVM volume group is lost. I ran Boot Repair from the Ubuntu Secure Remix Live CD and got the following URL: http://paste.ubuntu.com/1518253/

A brief history of my system:
- installed Ubuntu 12.10 32-bit on 2nd january on an Acer Aspire 5737Z 32-bit with 4Gb RAM, 120Gb SSD on an LVM partition
- updated nVidia drivers around the 8th january, seemed to work OK (though my Launcher's auto-hide functionality got messed up and I lost the graphical boot logo)
- installed updates on 10th january, immediately after that I booted my old 11.10 Ubuntu from external HDD; not sure which one caused the problem but since then, I am not able to boot my 12.10 on my internal SSD, I get the console "Ubuntu" loading screen and after waiting 30 sec I get dropped to (initramfs) with roughly the following messages (can write them down exactly if necessary):

Gave up waiting for root device
ALERT! /dev/mapper/ubuntu-root does not exist

When booting from external HDD or from LiveCD, I can only mount the boot partition of my SSD (255MiB). Checking with pvscan:

ubuntu@ubuntu:~$ sudo pvscan
  Incorrect metadata area header checksum on /dev/sda5 at offset 4096
  PV /dev/sda5 lvm2 [111.55 GiB]
  Total: 1 [111.55 GiB] / in use: 0 [0 ] / in no VG: 1 [111.55 GiB]

Checking with vgscan, I get the following message:

ubuntu@ubuntu:~$ sudo vgscan
  Reading all physical volumes. This may take a while...
  Incorrect metadata area header checksum on /dev/sda5 at offset 4096
  No volume groups found

I would like to recover my system to spare my setup time and to save some valuable data. Please help, let me know if you need any more details. Thank you in advance!

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.