How to Add a Second Drive to Ubuntu

Introduction

This guide shows how to add a second disk to an Ubuntu PC, mount it at /data, and make it persistent after reboot.

Step 1: Verify the new disk is visible

sudo lsblk -f

Confirm your new disk appears (for example as /dev/sdb).

Step 2: Partition the new disk (recommended)

sudo parted /dev/sdb --script mklabel gpt
sudo parted /dev/sdb --script mkpart primary ext4 0% 100%

Step 3: Format the partition as ext4

sudo mkfs.ext4 -F /dev/sdb1

Step 4: Create a mount point

sudo mkdir -p /data

Step 5: Mount the disk temporarily to test

sudo mount /dev/sdb1 /data

Check it mounted correctly:

lsblk -f

Step 6: Make the mount permanent (survives reboots)

Get the UUID of the partition:

sudo blkid /dev/sdb1

Copy the UUID value (looks like 12345678-1234-1234-1234-123456789abc), then open fstab:

sudo nano /etc/fstab

Add this line at the bottom (replace with your actual UUID):

UUID=your-actual-uuid-here   /data   ext4   defaults,noatime,discard   0   2

discard is optional. Many systems use defaults,noatime and rely on periodic TRIM (fstrim.timer) instead.

Step 6.5: Validate fstab before reboot

sudo mount -a

If no error is shown, your fstab entry is valid.

Step 7: Set permissions (optional but recommended)

sudo chown -R $USER:$USER /data

Final check

Reboot and verify the mount is still present:

lsblk -f