Amazon Elastic Block Store (EBS)
Amazon Elastic Block Store (EBS) provides persistent block storage volumes for use with Amazon Elastic Compute Cloud (EC2) instances. EBS volumes are network-attached and designed for high availability and durability, making them suitable for a wide range of workloads, from boot volumes to demanding enterprise applications.
Key Characteristics of EBS
EBS offers persistent, high-performance block storage for EC2 instances.
EBS volumes are attached to an EC2 instance and behave like raw, unformatted block devices. They persist independently of the life of the EC2 instance, meaning data remains available even if the instance is stopped or terminated (depending on volume configuration).
Unlike instance store volumes, which are physically attached to the host computer and are ephemeral, EBS volumes are network-attached. This allows them to be detached from one EC2 instance and attached to another within the same Availability Zone. EBS is designed for durability, with data replicated within an Availability Zone to protect against component failure. Performance characteristics, such as IOPS and throughput, can be provisioned based on the specific volume type chosen.
EBS Volume Types
AWS offers several EBS volume types, each optimized for different use cases and cost profiles. Choosing the right volume type is crucial for balancing performance and cost.
| Volume Type | Primary Use Case | Performance Metric | Key Features |
|---|---|---|---|
| General Purpose SSD (gp2/gp3) | Boot volumes, low-latency interactive applications, development/test environments | IOPS & Throughput | Balanced price-performance, burstable performance (gp2), provisionable performance (gp3) |
| Provisioned IOPS SSD (io1/io2) | I/O-intensive enterprise applications, large databases, transactional workloads | Provisioned IOPS | Highest performance SSD, consistent low latency, durable |
| Throughput Optimized HDD (st1) | Throughput-intensive workloads, big data, data warehouses, log processing | Throughput | Low cost, high throughput, optimized for sequential I/O |
| Cold HDD (sc1) | Infrequently accessed workloads, cost-sensitive storage, large sequential file transfers | Throughput | Lowest cost HDD, optimized for infrequent access and sequential I/O |
EBS Snapshots
EBS snapshots are incremental backups of your EBS volumes, stored in Amazon S3. They are point-in-time copies that can be used to create new EBS volumes, restore data, or migrate data across Availability Zones and AWS Regions.
Snapshots provide a durable, incremental backup mechanism for EBS volumes.
When you create a snapshot, only the blocks on the volume that have changed since the last snapshot are transferred to S3. This makes subsequent snapshots faster and more cost-effective. Snapshots are versioned, allowing you to track changes over time.
Snapshots are stored redundantly across multiple Availability Zones within a region, ensuring their durability. You can create snapshots manually or automate the process using AWS Data Lifecycle Manager. Restoring a snapshot involves creating a new EBS volume from it. The time it takes to create a new volume from a snapshot depends on the size of the snapshot and the volume type.
EBS Encryption
EBS encryption encrypts data at rest and in transit between the EC2 instance and the volume. This helps protect sensitive data and meet compliance requirements.
When EBS encryption is enabled, all data written to the volume, including snapshots, is encrypted using AES-256 encryption. The encryption keys are managed by AWS Key Management Service (KMS).
EBS Volume Lifecycle Management
Effective management of EBS volumes involves understanding their lifecycle, from creation to deletion, and implementing strategies for performance optimization and cost control.
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EBS vs. Instance Store
| Feature | Amazon EBS | Instance Store |
|---|---|---|
| Persistence | Persistent (independent of EC2 instance lifecycle) | Ephemeral (data lost when instance stops or terminates) |
| Attachment | Network-attached | Physically attached to the host computer |
| Durability | High (replicated within AZ) | Low (data lost on hardware failure) |
| Performance | Configurable (SSD/HDD, IOPS/throughput) | High, low latency (direct attachment) |
| Use Case | Boot volumes, databases, applications requiring persistent storage | Temporary storage, caching, scratch space |
Key Considerations for Cloud Solutions Architects
As a Cloud Solutions Architect, understanding EBS is critical for designing resilient, performant, and cost-effective solutions. Key considerations include selecting the appropriate volume type for each workload, implementing robust backup and disaster recovery strategies using snapshots, and leveraging EBS encryption for data security.
EBS volumes are persistent and survive EC2 instance restarts or terminations, while instance store volumes are ephemeral and their data is lost when the instance stops or terminates.
Provisioned IOPS SSD (io1/io2) volumes are designed for such high-performance, I/O-intensive workloads.
EBS snapshots are stored in Amazon S3 and are incremental, meaning only blocks that have changed since the last snapshot are transferred, making them efficient in terms of storage and transfer time.
Learning Resources
The official AWS page detailing EBS features, volume types, and common use cases. Essential for understanding the core capabilities.
A comprehensive guide to the different EBS volume types, their performance characteristics, and when to use each. Crucial for performance optimization.
Learn how to create, manage, and restore EBS snapshots, a fundamental aspect of data backup and recovery on AWS.
Understand how to enable and manage EBS encryption to secure your data at rest and in transit.
A blog post that clearly contrasts EBS and instance store volumes, helping to clarify their distinct purposes and benefits.
While a book, this often has online companion materials or is a primary source for exam preparation, covering EBS in detail.
A video tutorial explaining the nuances of EBS volume performance, including IOPS, throughput, and burst credits.
A video demonstrating how to manage the lifecycle of EBS volumes, including creation, attachment, detachment, and deletion.
A Wikipedia overview of Amazon EBS, providing a general understanding and historical context of the service.
This blog post discusses how to use AWS Storage Lens to gain visibility into your storage usage and performance, which is highly relevant for EBS management.