Key Details
My GPT layout drive has the following partition layout:
/dev/sda---|
|sda1 - Windows Recovery Partition
|sda2 - EFI Partition (Shared, Windows and Linux)
|sda3 - Windows Primary Partition
|sda4 - LUKS encrypted LVM partition
--------| /dev/mapper/volume-group-root: Linux root "/"
--------| /dev/mapper/volume-group-swap_1: Linux swap
Current Problem:
On boot, GRUB immediately prompts for the "master key". Entering the LUKS password allows the GRUB boot menu to open.
After selecting the linux OS to boot, another password prompt appears to unlock the LVM partition.
The second prompt makes sense - but why does that first one appear?
The Usual Answer
GRUB needs to decrypt the drive to read the boot files
This would make sense, but my GRUB installation should be sharing the unencrypted EFI partition with Windows. There are definitely boot files there anyway...
The steps I followed:
sudo mount /dev/mapper/volume-group-root /mnt
sudo mount /dev/sda1 /mnt/boot/efi
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot /mnt
grub-install /dev/sda
update-grub
Unfortunately the problem persists. Any thoughts or troubleshooting advice appreciated.
N.B - I suspect that grub placed the files in the EFI partition, but is incorrectly configured such that it tries to look in the wrong place on boot? Both the Windows and Linux OSes boot fine though. Not sure how to investigate this.
Further Information
- The current EFI partition is not inside the encrypted LVM. (Apologies if my diagram is unclear, advice welcome on how to make it clearer!)
- You answer suggests I need a /boot partition and a seperate EFI partition (I think), the trouble I am having is that various internet sources suggest that only one EFI partition is needed:
This table states /boot or EFI
This answers states /boot/efi is a convention and not necessary
and finally, this source states that I can get linux to share the Windows EFI partition without any issues, which is my aim here.
Maybe this is all fstab/other config related rather than partition issues?