Can't access luks-encrypted system partition anymore

[John Wiersba]

Have you tried sudo modprobe dm-mod ?

Here's my cheatsheet for off-the-live-cd LUKS/LVM decryption:

# RESCUE ENCRYPTED PARTITION

# download and copy cryptsetup and lvm2 .deb files to /boot/rescue
# apt-get -d install cryptsetup lvm2
# see package files in /var/cache/apt/archives

# /dev/sda1 is my /boot. /dev/sda2 is my crypto partition, containing
# volume group vg1 with logical partitions lvswap, lvroot, lvdata

# need packages cryptsetup (encrypted partition tools) and lvm2 (logical
# volume manager); install from internet (apt-get) or from local .deb files

# either use direct package installation (I pre-downloaded into /boot/rescue)...
sudo mkdir /media/boot
sudo mount /dev/sda1 /media/boot
sudo dpkg -i /media/boot/rescue/cryptsetup*.deb /media/boot/rescue/lvm2*.deb

# or use network-based package download/installation
sudo apt-get install cryptsetup lvm2

# insert kernel modules that we will need
sudo modprobe dm-crypt
sudo modprobe dm-mod

# unlock the sda2 partition and call it MYTAG
sudo cryptsetup luksOpen /dev/sda2 MYTAG
Enter LUKS passphrase:
key slot 0 unlocked.
Command successful.

# now that we have unlocked the encryption, deal with the lvm

sudo vgscan # scan for all volume groups
Reading all physical volumes. This may take a while...
Found volume group "vg1" using metadata type lvm2

# make the vg1 volume group active; if you don't give it a volume group as
# an argument it'll make them all active
sudo vgchange -ay [vg1]

sudo lvscan # list logical volumes and their /dev path
ACTIVE '/dev/vg1/lvswap' [2.00 GB] inherit
ACTIVE '/dev/vg1/lvroot' [10.00 GB] inherit
ACTIVE '/dev/vg1/lvdata' [60.00 GB] inherit

# mount a logical volume; don't do this if you need to run fsck on it
sudo mkdir /media/root
sudo mount /dev/vg1/lvroot /media/root

# to reverse the process and unmount everything, do the following

sudo umount /media/root

# the following command will issue a somewhat confusing message
sudo vgchange -an [vg1]
0 logical volume(s) in volume group "vg1" now active

sudo cryptsetup luksClose MYTAG

[F W Adams]

Hi John,

I solved my #30 problem. As expected I felt a bit ridiculous.

Symtoms:
Boot up as normal, enter the password and get in.
Boot up from CD, not able to get access.

Solution:
There was an "@" sign in the password, and I am in the UK. These two things together caused the problem. It seems that on the main system this was fine, I'm not sure at what stage the kb was set up as a uk one. Anyway it was never a problem.

Booting from the CD at no stage is the kb changed to uk ( of course ). When I typed the @ it came out as ", I couldn't see it on the screen so didn't realise. This means I was always entering the wrong password even when hitting the right keys. Big relief now, I can get to change things from the CD now.

Your list looks useful, I'll take a copy, thanks.