Amazon EC2 Instance Storage - AWS Storage Services Overview

Amazon EC2 Instance Storage

Amazon EC2 instance store volumes (also called ephemeral drives) provide temporary block-level storage for many EC2 instance types. This storage consists of a preconfigured and pre-attached block of disk storage on the same physical server that hosts the EC2 instance for which the block provides storage. The amount of the disk storage provided varies by EC2 instance type. In the EC2 instance families that provide instance storage, larger instances tend to provide both more and larger instance store volumes.

Note that some instance types, such as the micro instances (t1, t2) and the Compute-optimized c4 instances, use EBS storage only with no instance storage provided. Note also that instances using Amazon EBS for the root device (in other words that boot from Amazon EBS) don’t expose the instance store volumes by default. You can choose to expose the instance store volumes at instance launch time by specifying a block device mapping. For more information, see Block Device Mapping in the Amazon EC2 User Guide.

AWS offers two EC2 instance families that are purposely built for storage-centric workloads. Performance specifications of the storage-optimized (i2) and dense-storage (d2) instance families are outlined in the following table.

SSD-Backed Storage-Optimized (i2) HDD-Backed Dense-Storage (d2)

Use

Cases

NoSQL databases, like Cassandra and MongoDB, scale out transactional databases, data warehousing, Hadoop, and cluster file systems. Massively Parallel Processing (MPP) data warehousing, MapReduce and Hadoop distributed computing, distributed file systems, network file systems, log or data-processing applications
Read Performance 365,000 Random IOPS 3.5 GiB/s*
Write Performance 315,000 Random IOPS 3.1 GiB/s*
Instance Store Max. Capacity 6.4 TiB SSD 48 TiB HDD
Optimized For Very high random IOPS High disk throughput
* 2MiB block size