CentOS: Encrypted Filesystem

Pick a volume to encrypt and mount. This should be an empty volume, as this process completely erases all of the content on this volume. For this example, /dev/sda3 is being encrypted and mounted at /mnt/secure.
Prepare the volume
```
cryptsetup luksFormat /dev/sda3
```
Create the encrypted virtual device. This will be created at /dev/mapper/secure (replace "secure" with whatever you want to call it. This is an arbitrary value)
```
cryptsetup luksOpen /dev/sda3 secure
```
Create a filesystem on this virtual device
```
mke2fs -j /dev/mapper/secure
```
Create the mountpoint
```
mkdir -p /mnt/secure
```
Get the UUID of this device
```
cryptsetup luksUUID /dev/sda3
```

Add this UUID to /etc/crypttab

luks-d77eb752-8a90-4d94-ae9f-2bec0a22c5d3 UUID=d77eb752-8a90-4d94-ae9f-2bec0a22c5d3 none