EC2 Storage: Instance Store vs EBS
Understand when to use ephemeral instance store versus persistent EBS volumes and how to choose the right EBS volume type.
EC2 Storage Options Overview
EC2 instances can use two types of local storage: Instance Store and Amazon EBS (Elastic Block Store). Instance Store is physically attached to the host server, offering very high IOPS and throughput but with a critical caveat—data is lost when the instance stops or terminates. EBS provides persistent network-attached block storage that survives instance stop/start/termination. Understanding when to use each is a recurring topic on the SAA-C03 exam.
Instance Store: Ephemeral Storage
Instance Store (also called ephemeral storage) consists of NVMe SSDs physically attached to the host hardware that runs your EC2 instance. Data in the instance store is lost whenever the instance is stopped, hibernated, or terminated, or if the underlying hardware fails. However, data persists through a reboot. Instance Store is ideal for: buffer/cache/scratch data, temporary files, data that is replicated across a fleet (e.g., Cassandra nodes). Not all instance types include Instance Store; look for the d suffix (e.g., i3.xlarge, m5d.large).
# List NVMe block devices on an Instance Store instance
lsblk
# Example output:
# NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
# nvme0n1 259:0 0 500G 0 disk /
# nvme1n1 259:1 0 900G 0 disk <- instance storeAll lessons in this course
- Launching Your First EC2 Instance
- Instance Types and Pricing Models
- Security Groups and Key Pairs
- EC2 Storage: Instance Store vs EBS