5.3. Reinstall the secure system and keep data in home directory

In case of a major issue you may have to reinstall your system from scratch.

Boot on Ubuntu Alternate image ubuntu-12.04.1-alternate-i386.iso

Enter the name of the computer
Enter the full name of the main user
Enter the username for the account
Choose a password and enter it twice
Do not select to encrypt home directory (We will reused the encrypted partition already existing into the system)
Set clock timezone
Partition disks: Manual
Select: Configure encrypted volume
- Keep current partition layout and configure encrypted volumes: Yes
- Activate existing encrypted volume
  - Enter the pass phrase
You will see the LVM volumes in the disk partition description.
Define mounting point as described in the previous chapter (Format the partition / and /boot but do not format the partition /home)
Install the OS
Reboot

After this installation /boot and / have been recreated from scratch. It is then required to reapply the configuration described in previous chapter. If you use a keyfile to unlock the secured partition, this file should be reinstalled in the /boot partition from the backup you did. If you previously saved the installed packages into a file installed-packages as described into A secure place to backup my data, it is possible to restore to reinstall them with the following commands:

apt-get update
apt-get upgrade
dpkg --set-selections < installed-packages
apt-get -u dselect-upgrade