How do I install Ubuntu 10.04 with full disk encryption alongside other operating systems?

Question

I always used the Full Disk Encryption option of the alternate installer, but now I need to keep another OS running in the first partition but that option seems only to be able to use the whole disk. I tried to manually set up the encrypted volume and then an LVM on top of it with the partitions I need but the grub install failed (with no more information than that). I guess I need some additional step or maybe the boot partition should be out of the lvm.

I searched for instructions on how to do this but couldn't find any, I could try again this time with the boot partition but then that might be right but still missing something, so I'm asking to see if I can save some time and patience and also to document how to do it.

Answer 1

You should be able to use truecrypt.org to do this.

Using system encryption and a password at boot.

Answer 2

Grub needs a separate /boot partition without lvm and/or encryption. I don't recall which one caused the trouble but the solution was to create a small (like 150MB) plain ext2 partition and set it up as "mountpoint=/boot". Then use the rest of the free disk space as "physical volume for encryption" and create root/swap within.