What is Amazon EBS Volumes?
Amazon EBS is an abbreviation of “Elastic Block Storage“. Amazon EBS volume is a block-level storage device. EBS volumes can be used as primary storage for data that requires frequent updates, such as the system drive for an instance or storage for a database application. You can also use them for throughput-intensive applications that perform continuous disk scans. EBS volumes persist independently from the running life of an EC2 instance.
Amazon EBS contains the following volume types.
- General Purpose SSD (gp2)
- Provisioned IOPS SSD (io1 and io2)
- Throughput Optimized HDD (st1)
- Cold HDD (sc1)
- Magnetic (standard, an old generation type)
You can attach multiple EBS volumes to a single instance. The volume and instance must be in the same Availability Zone. Depending on the volume and instance types, Multi-Attach can be used to mount a volume to multiple instances at the same time.
EBS Volume Types
There are various difference in terms performance characteristics and price, allowing you to optimize your storage performance and cost. The volumes types fall into two categories.
- SSD-backed volumes optimized for transactional workloads involving frequent read/write operations with small I/O size, where the performance attribute is IOPS.
- HDD-backed volumes optimized for large streaming workloads where throughput (measured in MiB/s) is a better performance measure than IOPS.
There are various factors that affect the performance of EBS volumes, such as instance configuration, I/O characteristics, and workload demand.
EBS Volume Characteristics
The below table describes the use cases and performance characteristics for each volume type.
|Solid-State Drives (SSD)||Solid-State Drives (SSD)||Hard Disk Drives (HDD)||Hard Disk Drives (HDD)|
|Volume Type||General Purpose SSD (gp2)*||Provisioned IOPS SSD ( io1 and io2 )||Throughput Optimized HDD (st1)||Cold HDD (sc1)|
|Description||General purpose SSD volume that balances price and performance for a wide variety of workloads||Highest-performance SSD volume for mission-critical low-latency or high-throughput workloads||Low-cost HDD volume designed for frequently accessed, throughput-intensive workloads||Lowest cost HDD volume designed for less frequently accessed workloads|
|API Name||gp2||io1 and io2||st1||sc1|
|Volume Size||1 GiB – 16 TiB||4 GiB – 16 TiB||500 GiB – 16 TiB||500 GiB – 16 TiB|
|Max. IOPS/Volume||16,000 (16 KiB I/O) *||64,000 (16 KiB I/O)||500 (1 MiB I/O)||250 (1 MiB I/O)|
|250 MiB/s *||1,000 MiB/s||500 MiB/s||250 MiB/s|
|Max. Throughput/Instance||4,750 MB/s||4,750 MB/s||4,750 MB/s||4,750 MB/s|
|Amazon EBS Multi-attach||Not supported||Supported in io1 but not supported in io2||Not supported||Not supported|
|Durability||99.8% – 99.9% durability (0.1% – 0.2% annual failure rate)||99.999% durability (0.001% annual failure rate) in io2 and 99.8% – 99.9% durability (0.1% – 0.2% annual failure rate) in io1||99.8% – 99.9% durability (0.1% – 0.2% annual failure rate)||99.8% – 99.9% durability (0.1% – 0.2% annual failure rate)|
Critical business applications that require sustained IOPS performance, or more than 16,000 IOPS or 250 MiB/s of throughput per volume.
Large database workloads, such as:
While creating volume type, default volume type is General Purpose SSD (gp2).
Hence, you got deep understanding of Amazon EBS Volumes. In our upcoming tutorials we will lighten other AWS Services, so stay tuned.