Format the Harddrive
# For security purpose it could be wise to rewrite the harddrive.
# The process time depends on the size of the disk.
# Assume the disk is /dev/sda
# (Option A) Write zero to every block in the harddrive.
sudo dd if=/dev/zero of=/dev/sda bs=4K
# (Option B) For most secure (could takes days).
sudo dd if=/dev/urandom of=/dev/sda bs=4K
# Create partition, use the whole disk.
# If necessary delete old partitions.
sudo fdisk /dev/sda
n (create new partition)
p (primary)
(enter to use default values)
w (write and exit)
# Create LUKS partition.
sudo cryptsetup luksFormat -c aes -s 256 -h sha256 /dev/sda1
# Open LUKS partition.
sudo cryptsetup luksOpen /dev/sda1 luksUsb
# Format the partition.
sudo mkfs.ext4 -L data /dev/mapper/luksUsb
# Create mount point.
sudo mkdir /mnt/data
Mount the Disk
# Mount partition to change the ownership.
sudo mount /dev/mapper/luksUsb /mnt/data
sudo chown -R [User]:[Group] /mnt/data
References