[plug] Ubuntu dapper upgrade with lvm

[Patrick Coleman]

Hey all,
Yesterday I had a crack at upgrading my ubuntu from breezy to dapper.
Everything was looking AOK until I made the mistake of rebooting
(after everything had finished updating). The system is now more or
less unbootable. I run LVM (no raid) with each logical volume using
reiserfs.

Here's what I get on bootup:

<happy boot messages up to here>
  8 logical volume(s) in volume group "main" now active
Done.
/init: 1: cannot open /dev/root: No such device or address
Begin: Running /scripts/local-premount
[4294686.771000] Attempting manual resume
Done.
Usage: modprobe [-v] [-V] [-C config-file] [-n] -[-i] -[q] [-Q] [-b]
[-o <modname] <modname> [parameters...]
modprobe -r [-n] [-i] [-v] <modulename> ...
mount:
cannot read /dev/fstab: No such file or directory
Begin: Running /scripts/local-bottom
Done.
Done.
Begin: Running /scripts/init-bottom...
mount: mounting /root/dev on /dev/.static/dev/ failed: No such file or directory
Done.
mount: Mounting /sys on /root/sys failed: No such file or directory
mount: Mounting /proc on /root/proc failed: No such file or directory
Target filesystem doesn't have /sbin/init

BusyBox v1.01 (Debian 1:1.01-ubuntu1) Built-in shell (ash)
Enter `help` for a list of built-in commands

/bin/sh: can't access tty; job control turned off
#

If I try `mount -t reiser /dev/mapper/main-root /root` at that busybox
prompt I get an `Invalid argument` error from mount.

I can boot off a ubuntu livecd (hoary) and chroot into my root
partition. From there I have been trying to fix the problem. I have
tried different kernel versions, architectures, reinstalling
initcramfs-tools, reinstalling the kernel, and reinstalling lvm2.

I tried switching to grub (I'm currently on lilo, which I now hate
after having tried grub a few months ago) but realised that would
require me to create another non-lvm partition to hold /boot, which I
didn't feel up to at 2am this morning. It may be something to try as a
last resort if I can dig out my copy of partitionmagic.

I even tried modifying the initrd scripts to try and fix that modprobe
error above (that was an abject failure - Kernel panic: Tried to kill
init!).

So, I am completely stumped. Any suggestions at all, even if they
involve voodo, are welcome.

Thanks in advance,
Patrick
--
http://www.labyrinthdata.net.au