Thanks once again to KaosuX - disk encryption has been removed, and my OS is back working once more.
For anyone else who is contemplating doing something similar, here are a few extra details that I omitted in my original post.
- I am running LVM
- I found a spare SATA drive that I could use to direct copy from original disk to new disk
The process I followed was the same as advised by KaosuX, once I had created a LiveCD and booted from it (I did this using a thumbdrive, which left my DVD slot spare for a second HD)
- install crypt and lvm
- load the modules
sudo apt-get install cryptsetup lvm2
- open the encrypted partition
sudo modprobe dm-crypt
I then had to go through the LVM commands so that the logical volume would be detected. I found excellent instructions for doing this in http://linuxwave.blogspot.com.au/200...tu-livecd.html
cryptsetup luksOpen /dev/sda5 crypt
Once I had mounted the relevant partitions, it was a simple matter to copy the contents from my original disk to the second disk. In my case, the second disk had also been initialised using LVM and similar sized partitions created.
Note: On the encrypted disk, the boot sector was in a separate partition (I guess because it can't be encrypted). In the target disk (the non-encrpted one), the boot sector is in the same partition as the remainder of my OS.
Having mounted the old and new partitions at ~/oldDisk and ~/newDisk respectively, I used the following command to copy every file across.
Note the '/' at the end of oldDisk....this tells rsync to copy the contents of oldDisk to the target.
rsync -a ~/oldDisk/ ~/newDisk
Finally, a couple of gotchas I experienced...
On bootup with the new disk, I got the following error message
I eventually figured out that this was caused by an incorrect entry in my /etc/fstab file.
The disk drive for /boot is not ready yet or not present
The entry contained the UUID for the old disk, i.e.
UUID=7df57494-c161-4a65-ae9d-4868832ee8e9 /boot ext2 defaults 0 2
Changing this to the UUID value of my new disk fixed the problem - use the blkid command to find out what this value is.
The second problem concerned my NVIDIA display driver...not sure why it screwed up, but I could only get low resolution graphics until I reinstalled the drivers. I did this by following instructions at http://www.noobslab.com/2012/10/install-latest-nvidia-drivers-in-ubuntu.html
In essence, here are the commands I ran.
And that was it...now have everything running smoothly (and probably slightly quicker) without any LUKS disk encryption.
sudo apt-add-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
sudo apt-get install nvidia-current