Partition the disk with gdisk /dev/sdb as type Linux LVM 8e00.

Setup LUKS

cryptsetup luksFormat /dev/sdb1
cryptsetup luksOpen /dev/sdb1 sdb1_crypt
pvcreate /dev/mapper/sdb1_crypt
vgcreate server-hdd-vg /dev/mapper/sdb1_crypt
lvcreate -l 100%FREE -n root /dev/server-hdd-vg
mkfs.ext4 /dev/server-hdd-vg/root
mkdir /mnt/hdd
mount /dev/server-hdd-vg/root /mnt/hdd

Unlock disk automatically

Add a LUKS keyfile.

Generate keyfile

sudo dd if=/dev/urandom of=/root/keyfile-sdb1_crypt bs=1024 count=4
chmod 0400 /root/keyfile-sdb1_crypt
cryptsetup luksAddKey /dev/sdb1 /root/keyfile-sdb1_crypt

Get the UUID for sdb1

ls -l /dev/disk/by-uuid

Edit /etc/crypttab

sdb1_crypt UUID=<DISK UUID> /root/keyfile-sdb1_crypt luks

Get the UUID for /dev/mapper/server--hdd--vg-root


Edit /etc/fstab

UUID=<MAPPER UUID>     /mnt/hdd     ext4     defaults     0     2

Adding a disk to an existing volume group

vgextend server-hdd-vg /dev/mapper/sdc1_crypt
lvextend /dev/server-hdd-vg/root /dev/mapper/sdc1_crypt
resize2fs /dev/server-hdd-vg/root


Automatically Unlock LUKS Encrypted Drives With A Keyfile

Adding an external encrypted drive with LVM to Ubuntu Linux