How to boot from existing LUKS partition? (dual boot)

Question

I installed elementary os on my laptop that already has some OS's installed. The way I achieve this is;

• I have an efi partition /dev/sda1
• I have a LUKS container in /dev/sda2
• The LUKS container has a LVM volume group names Linux
• I have a logical volume named Elementary under the LVM, accessible at /dev/mapper/Linux-Elementary

I already have a boot loader (rEFInd) configured, so what I did when I installed elementary is;

• Booted live USB
• Used terminal to launch the installer with --no-boot parameter; since I already have a boot loader.
• Used cryptsetup open to decrypt the LUKS container at /dev/sda2
• Installed EOS on /dev/mapper/Linux-Elementary
• Copied all files in /boot to my ESP and edited fstab accordingly.

However, this leaves me with a couple hiccups. I suspect the initrd does not have any decryption built into it, because if I supply the kernel parameter cryptdevice=UUID=<UUID-here>:cryptroot no decrpytion happens, and after a while I am dumped to busybox initramfs. There is a function in busybox called cryptroot unlock but it gives me an output sed: /conf/conf.d/cryptroot: No such file or directory when I run it. I am unfamiliar with ubuntu based methods of doing this; how do I add decryption to initramfs? (I can chroot in from my other distros to run commands)

I also see a lot of files under /boot, (config-*, abi-*, retpoline-*, System.map-*) which leads me to think that regular kernel parameters might not be enough. (I use rw quiet splash root=/dev/Linux/Elementary in addition to the cryptdevice parameter) Can anyone guide me on what kernel parameters I should use? (Or share your working refind_linux.conf?)

Answer 1

Sorry I just read this article today, I think its not relevant anymore, but if you or someone else still has the same problem try the following steps. Ensure that you have put "dm-crypt" in your /etc/modules file of your elementary OS installation. You should also put GRUB_CMDLINE_LINUX_DEFAULT="kopt=root=/dev/mapper/vgubuntu-root" into the /etc/default/grub configuration file of your elementary installation if you are using grub as a boot loader and do an update-grub with chroot.