Creating a LUKS container on an LVM volume
Install the necessary packages
apt install cryptsetup
Create a volume group and a logical volume
vgcreate vg /dev/sdb
lvcreate --extents 100%FREE vg --name lv
Initialize a container
cryptsetup --verbose --verify-passphrase luksFormat --type luks2 /dev/vg/lv
Open the container
cryptsetup open /dev/vg/lv data
Create a filesystem in the container
mkfs -t xfs /dev/mapper/data
Mount the filesystem
mount /dev/mapper/data /mnt
Create a header backup
cryptsetup luksHeaderBackup /dev/vg/lv --header-backup-file /root/header.luks