EC2 Volume Types

Mar 25, 2020 • 2 min read
AWS • Knowledge

Instance Store vs. Elastic Block Store

Preface

Since I'm currently going through the AWS Certified Solutions Architect course offered by Linux Academy, I'm going to need to write things out so that they make a bit more sense to me. Today, it's going to be the differences between Instance Stores and Elastic Block Stores.

Instance Store

• Provides temporary block level storage for an EC2 instance.
• Ephemeral; best used to store data temporarily that frequently changes.
  • ex. buffers, cache or scratch data.
• Data will not survive if the instance is stopped, terminated or if the underlying drive just fails.

More information can be found in the Instance Store documentation.

Elastic Block Store

• Provides either SSD or traditional HDD backed volumes, depending on need, performance requirements and/or price.
  • SSD volumes:
    • Best for transactional workloads such as frequent read / write operations.
    • Two types of SSDs — General purposed (gp2) and Provisioned IOPS (io1).
      • General purpose favors balance of price and performance.
      • IOPS favors high performance (mission-critical low-latency / high-throughput)
  • HDD volumes:
    • Best for larger streaming workloads where throughput is more desirable than IOPS.
    • Two types of HDDs — Throughput optimized (st1) and Cold HDD (sc1).
      • Throughput optimized is better used towards hot storage where data is frequently accessed and throughput is essential.
      • Cold HDD is low cost storage designed for less frequently accessed workloads such as archiving.

More information can be found in the Elastic Block Store documentation.

I'm not going to get into IOPS or I/O credit balances since I think those topics require their own page(s). This should serve as a great reference since my understanding after watching the video was still a bit hazy.

Next up — EBS Snapshots