GRUB error, possibly RAID-related, inability to boot
 

Hi,

I'm trying to get a laptop up and running. I've already nuked everything from orbit and paved over with, nominally, a fully-encrypted Ubuntu install, and when I rebooted off of the Live CD to try to load Ubuntu, it gave me a grub rescue screen.

So of course, I try the obvious:

grub rescue> ls
(hd0) (hd0,msdos1)

Attempting to ls into each of those gives me "error: unknown filesystem".

Attempting to run the boot-repair utility or the rescatux/grub fixer programs doesn't work. The latter gives me a long, unending chain of disk I/O errors and the former complains of there being a RAID and doesn't supply a button with which to even start the repair.

... halp? I have no idea what I'm doing at this point, having completely exhausted my own knowledge.

I can boot up from a LiveCD just fine, it's booting from the HDD's install that fails.

If there's any additional information I should supply, please let me know.

Results of df:

Filesystem 1K-blocks Used Available Use% Mounted on
/cow 6141876 26376 6115500 1% /
udev 6131760 4 6131756 1% /dev
tmpfs 2456752 876 2455876 1% /run
/dev/sr0 781312 781312 0 100% /cdrom
/dev/loop0 733312 733312 0 100% /rofs
tmpfs 6141876 8 6141868 1% /tmp
none 5120 0 5120 0% /run/lock
none 6141876 76 6141800 1% /run/shm
none 102400 56 102344 1% /run/user


Results of fdisk -l

Warning: ignoring extra data in partition table 5
Warning: ignoring extra data in partition table 5
Warning: ignoring extra data in partition table 5
Warning: invalid flag 0xce78 of partition table 5 will be corrected by w(rite)

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003c590

Device Boot Start End Blocks Id System
/dev/sda1 512 500223 249856 83 Linux
/dev/sda2 500734 1953536511 976517889 5 Extended
/dev/sda5 ? 1818976495 2093463169 137243337+ 52 CP/M

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

Well, I have no idea why, but reinstalling Ubuntu again (fifth time today) magically made it work.

Solved, I guess?