Chapter 13: Amazon EBS (Elastic Block Store)

13.6 Adding a new EBS volume

By Ravindra Bagale · Last updated: 25 September 2026

Chala, aata ek navin disk add karuya (let's add a new disk). Think of it like plugging a new external hard disk into your laptop — but technically, AWS attaches a network block device that appears as an NVMe disk, and you must format and mount it yourself.

Goal: add a 10 GiB gp3 disk to an instance and mount it permanently at /data.

Step 1 — Find the instance's Availability Zone

EC2 → Instances → select instance → Networking tab → Availability zone (e.g. ap-south-1a). Or on the instance:

TOKEN=$(curl -s -X PUT http://169.254.169.254/latest/api/token -H "X-aws-ec2-metadata-token-ttl-seconds: 60")
curl -s -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/placement/availability-zone; echo

Step 2 — Create the volume (same AZ!)

EC2 → Elastic Block Store → Volumes → Create volume → Volume type gp3 → Size 10 GiB → Availability Zone same as the instance → (optional) tick Encrypt this volume → add tag Name=data-vol → Create volume. Wait until state is Available.

Step 3 — Attach it

Select the volume → Actions → Attach volume → choose your instance → Device name /dev/sdf → Attach volume. State becomes In-use.

Step 4 — Identify the new disk

lsblk

NAME          MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
nvme0n1       259:0    0   20G  0 disk
└─nvme0n1p1   259:1    0   20G  0 part /
nvme1n1       259:4    0   10G  0 disk                 ← new, no filesystem, not mounted

Make sure it is empty (a brand-new volume shows data or nothing, not a filesystem):

sudo file -s /dev/nvme1n1        # "/dev/nvme1n1: data" means empty
lsblk -f /dev/nvme1n1

Step 5 — Create a filesystem

# XFS (recommended on Amazon Linux / CentOS; install xfsprogs on Ubuntu if you prefer XFS)
sudo mkfs -t xfs /dev/nvme1n1

# OR ext4 (common on Ubuntu)
# sudo mkfs -t ext4 /dev/nvme1n1

Step 6 — Create a mount point and mount

sudo mkdir -p /data
sudo mount /dev/nvme1n1 /data
df -hT /data

Step 7 — Make the mount permanent with /etc/fstab (UUID + nofail)

A plain mount is forgotten after reboot. Add an entry to /etc/fstab using the UUID:

sudo blkid /dev/nvme1n1
# /dev/nvme1n1: UUID="8a5c6f1e-2b3d-4c5e-9f10-1a2b3c4d5e6f" BLOCK_SIZE="512" TYPE="xfs"

sudo cp /etc/fstab /etc/fstab.bak           # always back up first
UUID=$(sudo blkid -s UUID -o value /dev/nvme1n1)
FSTYPE=$(sudo blkid -s TYPE -o value /dev/nvme1n1)
echo "UUID=$UUID  /data  $FSTYPE  defaults,nofail  0  2" | sudo tee -a /etc/fstab
cat /etc/fstab

Test the fstab entry before rebooting:

sudo umount /data
sudo mount -a                 # mounts everything in fstab; any error here means fix fstab NOW
sudo systemctl daemon-reload
df -hT /data

Step 8 — Use it

sudo chown $USER:$USER /data
echo "hello EBS" > /data/test.txt
sudo reboot
# after reconnecting:
df -hT /data && cat /data/test.txt

Common uses: move MySQL data (/var/lib/mysql), website files, logs or backups onto a separate volume so they survive root-volume problems and can be snapshotted separately.