Before implementing disk encryption, ensure you have:

• CentOS 7 installed.
• Terminal access with root user privileges or a user with sudo privileges.
• Sufficient backup of important data.

Step 1: Install Required Software

The first step is to install the cryptsetup software, which enables disk encryption using the Linux Unified Key Setup (LUKS) technology. Open the terminal and enter the following command:

sudo yum install cryptsetup -y

Step 2: Prepare Disk for Encryption

Before encryption, select the disk or disk partition you wish to encrypt. Use the fdisk -l command to identify the device name you want to encrypt. In this example, we'll encrypt the partition /dev/sdb1.

Note: This process will erase all data on the disk, so ensure you have a backup of all important data.

Step 3: Initialize and Encrypt the Disk

Initialize disk encryption with LUKS using the following command:

sudo cryptsetup luksFormat /dev/sdb1

You will be prompted to enter a password for encryption, which will be required for each access to the data on the encrypted disk.

Step 4: Open and Map the Encrypted Disk

After initializing encryption, open the encrypted disk with the command:

sudo cryptsetup open /dev/sdb1 disk_name

Replace disk_name with the name under which the encrypted disk will be accessible. This step creates a new device in /dev/mapper/, representing the encrypted disk.

Step 5: Format and Mount the Encrypted Disk

Now, format the encrypted disk to the desired file system, such as ext4:

sudo mkfs.ext4 /dev/mapper/disk_name

Then, mount the disk to the system:

sudo mount /dev/mapper/disk_name /mnt

Step 6: Configure Automatic Mounting at Startup

For automatic mounting of the encrypted disk at system startup, modify the /etc/crypttab and /etc/fstab files.

1. Add a line to /etc/crypttab:

   disk_name /dev/sdb1 none luks
   ​

2. And a line to /etc/fstab for mounting:

   /dev/mapper/disk_name /mnt ext4 defaults 0 2
   ​

 

Implementing disk encryption on CentOS 7 is a crucial step in protecting sensitive data. Follow the steps above to secure your disk using LUKS. Remember, the security of your data also depends on a strong and securely stored encryption password.