I think what I’d like to have is one unencrypted /boot partition and one encrypted physical LVM volume containing the rest of the disk with the volume groups /root, /home and /swap on which the system is installed.
If I prepare this before and then use the installer, it will only allow me to overwrite the existing LVM volumes. If I try to create the physical volume in the installer, I can not create the required volume groups.
This link pretty much describes the behavior:
https://tracker.pureos.net/T778
(e.g. case 4 would correspond to the second case mentioned above)
Unfortunately I can’t find the USB-Stick with the PureOS-2.1 distro which I used to install the system on my Librem15rev2, otherwsie I would try that one (not sure if it will work with a Librem15rev3, but maybe yes).
Could the problem be related to the fact that my disk is a 512GB NVMe Pro accessed through /dev/nvme0n1?
On my Librem15rev2, i have a Samsung 850 EVO M.2 SSD showing up as /dev/sdb. Don’t know if this makes a difference.