Elastic Block Store (EBS) Volume Types for AWS
Just as there isn’t one kind of hard drive, there isn’t one kind of EBS volume. Amazon Web Services (AWS) currently provides access to both Solid-State Drive (SSD) and Hard Disk Drive (HDD) volumes. SSD provides high-speed access, while HDD provides lower-cost access of a more traditional hard drive. Amazon further subdivides the two technologies into two types each (listed in order of speed):
- EBS Provisioned IOPS SSD: Provides high-speed data access that you commonly need for data-intensive applications that rely on moderately-sized databases.
- EBS General Purpose SSD: Creates a medium-high-speed environment for low-latency applications. Amazon suggests this kind of volume for your boot drive. However, whether you actually need this amount of speed for your setup depends on the kinds of applications you plan to run.
- Throughput Optimized HDD: Defines a high-speed hard drive environment, which can’t compete with even a standard SSD. However, this volume type will work with most common applications and Amazon suggests using it for big data or data warehouse applications. This is probably the best option to choose when money is an issue and you don’t really need the performance that SSD provides.
- Cold HDD: Provides the lowest-speed option that Amazon supports. You use this volume type for data you access less often than data you place on the other volume types (think data you use once a week, rather than once every day). This isn’t an archive option; it’s more like a low-speed option for items you don’t need constantly, such as a picture database.
As you move toward higher-speed products, you also pay a higher price. For example, at the time of writing, a Cold HDD volume costs only $0.025/GB/month, but an EBS Provisioned SSD volume costs $0.125/GB/month. You can find price and speed comparison details online. The table provided contains some interesting statistics. For example, all the volume types top out at 16TB and support a maximum throughput per instance of 800MB/s.