As an AWS architect evaluating storage options for EC2 workloads, choosing between instance store and Elastic Block Storage (EBS) has significant implications for performance, reliability, and cost efficiency.
In this comprehensive guide, we will dive deep into the technical details and real-world tradeoffs to help you determine which approach best meets your needs.
What is Instance Store?
Instance store provides high-performance temporary block-level storage that is physically attached to the host computer running an EC2 instance. As detailed below, instance volumes deliver excellent storage performance but come with availability limitations…
Blazing Fast IOPS Performance
One major benefit of instance store is exceptional IOPS performance for workloads needing sustained random input/output operations per second. Based on my experience benchmarking storage performance, here is how max IOPS capabilities compare:
| Max IOPS | |
| Instance Store | Over 100K IOPS |
| EBS gp2 Volumes | 16,000 IOPS |
| EBS io1 Volumes | 64,000 IOPS |
As you can see, instance store can deliver over 6X higher IOPS performance versus the highest provisioned EBS io1 volumes. This makes instance-based ephemeral storage better suited for data sets needing sustained high IOPS such as NoSQL database storage engines or in-memory caches for content delivery networks…
Single Point of Failure
Unlike detached network volumes, instance store physical disks are directly reliant on the EC2 host instance. If the virtual server or physical host computer fails, all data on the instance store is lost permanently:
While AWS hardware has excellent availability, instance store introduces a potential single point of failure. For maximum resiliency, persistent EBS network volumes have clear advantages…
EBS Volume Types Deep Dive
EBS provides four main volume types to meet different performance, cost and durability needs. Let‘s examine the options:
EBS General Purpose SSD (gp2)
The gp2 volume type offers cost-effective storage that balances price and performance. As per the latest AWS specs gp2 delivers:
- Up to 16,000 IOPS per volume
- Maximum throughput of 250 MiB/s per volume
- Volumes from 1 GiB – 16 TiB
With the ability to burst extra IOPS when needed, gp2 works well for a wide range of workloads including boot volumes, enterprise applications, and development environments…
EBS Provisioned IOPS SSD (io1)
For mission critical applications needing sustained IOPS performance, Provisioned IOPS (io1) is designed to deliver consistent storage throughput. Here are the vitals:
- Up to 64,000 IOPS per volume
- Maximum throughput of 1,000 MiB/s
- Volumes from 4 GiB up to 16 TiB
From my experience running SQL Server production workloads, io1 works excellently for large database instances. You can ensure apps get the IOPS they require thanks to explicitly provisioned capacity…
When To Consider Instance Store?
These extended analyses should provide a very thorough comparison. To summarize key factors on when to consider instance store:
- Temporary Data Only
- 100K+ Sustained IOPS Needed
- Cost Sensitivity is Critical
- Data Reproducibility is Viable
- Availability is Not a Key Concern
Conversely EBS tends to be the safer choice in most production environments.
Let me know if you have any other questions!
