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Amazon EBS

Amazon EBS Overview

  • Definition: Amazon Elastic Block Store (EBS) is a high-performance, scalable block storage service designed for use with Amazon EC2 instances, providing persistent storage for a wide range of workloads.
  • Key Features:
    • Offers multiple volume types optimized for different performance and cost needs (e.g., SSD, HDD).
    • Supports snapshots for backups, stored in Amazon S3.
    • Provides encryption, Multi-Attach, and elasticity (resize without downtime).
    • Integrates with AWS Backup, Auto Scaling, and other services.
  • Use Cases: Databases (e.g., MySQL, Oracle), enterprise applications (e.g., SAP), big data analytics, boot volumes for EC2, file systems.

1. EBS Core Concepts

Components

  • EBS Volume:
    • Block storage device attached to an EC2 instance via NVMe or iSCSI.
    • Persistent, independent of instance lifecycle.
    • Explanation: E.g., 100 GB volume for EC2 database storage.
  • Snapshot:
    • Point-in-time backup of a volume, stored in S3.
    • Incremental, only changed blocks are saved.
    • Explanation: E.g., snapshot of a 100 GB volume for DR.
  • Volume Types:
    • SSD-backed: gp3, gp2, io2, io1 (high performance).
    • HDD-backed: st1, sc1 (cost-effective for throughput-intensive).
    • Explanation: E.g., gp3 for general-purpose, io2 for mission-critical.
  • Availability Zone (AZ):
    • Volumes are AZ-specific; must be in the same AZ as the EC2 instance.
    • Explanation: E.g., volume in us-east-1a for EC2 in us-east-1a.

Volume Types

Type Use Case Performance Size Cost
gp3 (SSD) General-purpose, databases 3,000–16,000 IOPS, 125–1,000 MB/s 1 GB–16 TB ~$0.08/GB-month
gp2 (SSD) Boot volumes, dev/test 3,000–16,000 IOPS (burst), 250 MB/s 1 GB–16 TB ~$0.10/GB-month
io2 (SSD) Mission-critical (SAP, Oracle) Up to 256,000 IOPS, 4,000 MB/s 4 GB–64 TB ~$0.125/GB-month
io1 (SSD) High-performance, legacy 50–64,000 IOPS, 1,000 MB/s 4 GB–16 TB ~$0.125/GB-month
st1 (HDD) Big data, streaming 500 MB/s, 500 IOPS 125 GB–16 TB ~$0.045/GB-month
sc1 (HDD) Cold data, backups 250 MB/s, 250 IOPS 125 GB–16 TB ~$0.015/GB-month
- Explanation: gp3 is default for cost/performance; io2 for high IOPS; st1/sc1 for large, sequential workloads.

Key Updates (2024–2025):

  • io2 Block Express: Up to 256,000 IOPS, 4,000 MB/s, sub-millisecond latency for io2 volumes (available on Nitro-based instances).
  • Snapshot Encryption: Default encryption for new snapshots; re-encryption support for existing snapshots (March 2024).
  • Multi-Attach Enhancements: Supports up to 16 Nitro-based instances for io2/io1 (e.g., Oracle RAC).
  • Cost Allocation Tags: Track snapshot costs by project/environment (October 2024).

Key Notes:

  • Exam Relevance: Understand volume types, snapshots, and encryption.
  • Mastery Tip: Compare gp3 vs. gp2 and io2 vs. io1 for performance/cost.

2. EBS Performance Features

EBS supports high-performing workloads.

High IOPS and Throughput

  • gp3: 3,000 IOPS, 125 MB/s baseline; up to 16,000 IOPS, 1,000 MB/s.
  • io2 Block Express: Up to 256,000 IOPS, 4,000 MB/s, sub-ms latency.
  • Explanation: E.g., io2 for SAP HANA with high transactional throughput.

Elasticity

  • Purpose: Adjust performance dynamically.
  • Features:
    • Modify volume size, type, or IOPS/throughput without downtime.
    • Explanation: E.g., resize gp3 from 100 GB to 200 GB in seconds.

Burst Performance

  • gp2: Burst credits for up to 3,000 IOPS (based on volume size).
  • T3 Instances: Aligns with burstable EC2 for cost-efficient performance.
  • Explanation: E.g., gp2 bursts for dev/test spikes.

Multi-Attach

  • Purpose: Shared access.
  • Features:
    • io2/io1 volumes attach to up to 16 Nitro-based instances (same AZ).
    • Requires cluster-aware file system (e.g., GFS2, OCFS2).
  • Explanation: E.g., shared io2 volume for Oracle RAC cluster.

Key Notes:

  • Performance: io2 Block Express + elasticity = enterprise-grade.
  • Exam Tip: Know IOPS/throughput limits and Multi-Attach use cases.

3. EBS Resilience Features

Resilience ensures data availability and recovery.

Multi-AZ Snapshots

  • Purpose: Survive AZ failures.
  • Features:
    • Snapshots stored in S3, replicated across AZs in a Region.
    • Restore volumes in any AZ within the Region.
  • Explanation: E.g., restore snapshot from us-east-1a to us-east-1b.

Cross-Region Replication

  • Purpose: Disaster recovery.
  • Features:
    • Copy snapshots to another Region (manual or via AWS Backup).
    • Explanation: E.g., replicate EBS snapshot to us-west-2 for DR.

Fast Snapshot Restore (FSR):

  • Purpose: Speed up recovery.
  • Features:
    • Pre-initializes snapshots for instant restores (bypasses lazy loading).
    • Costs ~$0.0125/snapshot/AZ/hour.
  • Explanation: E.g., enable FSR for critical database snapshots.

Integration with AWS Backup

  • Purpose: Centralized DR.
  • Features:
    • Policy-driven backups, cross-region replication, PITR.
    • Explanation: E.g., daily EBS backups with 35-day retention.

Key Notes:

  • Resilience: Snapshots + FSR + AWS Backup = robust DR.
  • Exam Tip: Design DR with cross-region snapshots and AWS Backup.

4. EBS Security Features

Security aligns with SAA-C03’s secure architecture focus.

Encryption

  • At Rest:
    • All volume types support KMS encryption (AWS-managed or customer-managed keys).
    • Snapshots encrypted by default for new volumes (March 2024).
    • Explanation: E.g., encrypt root volume with custom KMS key.
  • In Transit:
    • NVMe/TLS for data between EC2 and EBS.
    • Explanation: E.g., secure data during volume access.

Access Control

  • IAM:
    • Controls volume/snapshot operations (e.g., ec2:CreateVolume).
    • Snapshot sharing with specific accounts or public.
    • Example: {"Effect": "Allow", "Action": "ec2:CreateSnapshot", "Resource": "arn:aws:ec2:us-east-1::volume/vol-123"}.
  • Resource-Based Policies:
    • Restrict snapshot access (e.g., allow only dev account).
  • Explanation: E.g., share encrypted snapshot with partner account.

Compliance

  • Certifications: HIPAA, PCI, SOC, ISO.
  • Explanation: E.g., deploy healthcare app with encrypted EBS.

Key Notes:

  • Security: KMS + IAM = compliant storage.
  • Exam Tip: Practice snapshot sharing and encryption policies.

5. EBS Cost Optimization

Cost efficiency is a key exam domain.

Pricing

  • Volumes:
    • gp3: ~$0.08/GB-month, $0.005/provisioned IOPS, $0.04/provisioned MB/s.
    • gp2: ~$0.10/GB-month.
    • io2: ~$0.125/GB-month, $0.065/provisioned IOPS.
    • st1: ~$0.045/GB-month.
    • sc1: ~$0.015/GB-month.
  • Snapshots:
    • ~$0.05/GB-month (incremental, S3-based).
  • FSR: ~$0.0125/snapshot/AZ/hour.
  • Free Tier: 30 GB gp2, 1 GB snapshots for 12 months.
  • Example: 100 GB gp3 (3,000 IOPS, 125 MB/s) + 50 GB snapshots ~$9.50/month.

Cost Strategies

  • Right-Sizing:
    • Use gp3 for cost/performance (20% cheaper than gp2).
    • Choose st1/sc1 for non-critical, sequential workloads.
  • Snapshot Management:
    • Delete unused snapshots to reduce S3 costs.
    • Use incremental snapshots to minimize storage.
  • Elasticity:
    • Resize volumes dynamically to avoid over-provisioning.
  • Tagging:
    • Use cost allocation tags for volume/snapshot cost tracking.
  • Explanation: E.g., tag snapshots with “Project:Analytics” for budgeting.

Key Notes:

  • Cost Savings: gp3 + incremental snapshots + tags = low costs.
  • Exam Tip: Calculate costs for gp3 vs. io2 and snapshot retention.

6. EBS Advanced Features

io2 Block Express

  • Purpose: Ultra-high performance.
  • Features:
    • 256,000 IOPS, 4,000 MB/s, sub-ms latency.
    • Available on Nitro-based instances (e.g., m5, r5).
  • Explanation: E.g., use for Oracle database with high IOPS.

Multi-Attach

  • Purpose: Shared storage.
  • Features:
    • io2/io1 volumes attach to 16 instances (Nitro-only).
    • Supports cluster-aware file systems.
  • Explanation: E.g., shared volume for high-availability SQL Server.

Elastic Volumes

  • Purpose: Dynamic resizing.
  • Features:
    • Modify size, IOPS, throughput, or type (e.g., gp2 to gp3) without detaching.
    • Explanation: E.g., upgrade to io2 during peak load.

Snapshot Archive

  • Purpose: Long-term storage.
  • Features:
    • Move snapshots to lower-cost archive tier (~$0.0125/GB-month).
    • 24–72 hour restore time.
  • Explanation: E.g., archive old database snapshots for compliance.

Key Notes:

  • Flexibility: Block Express + Multi-Attach = advanced workloads.
  • Exam Tip: Know snapshot archive and Multi-Attach limitations.

7. EBS Use Cases

Understand practical applications.

Databases

  • Setup: EC2 + io2 + AWS Backup.
  • Features: High IOPS, PITR via snapshots.
  • Explanation: E.g., MySQL with io2 for low-latency queries.

Boot Volumes

  • Setup: EC2 + gp3.
  • Features: Reliable, burstable performance.
  • Explanation: E.g., Amazon Linux 2 root volume.

Big Data

  • Setup: EC2 + st1.
  • Features: High throughput, low cost.
  • Explanation: E.g., Hadoop cluster with st1 volumes.

Disaster Recovery

  • Setup: Snapshots + cross-region replication.
  • Features: Fast restores, cross-AZ/Region.
  • Explanation: E.g., replicate EBS snapshots for DR.

8. EBS vs. Other Storage Services

Feature EBS EFS S3
Type Block Storage File Storage Object Storage
Workload Databases, boot volumes Shared file systems Backups, archives
Performance High IOPS, low latency Scalable, shared High durability
Cost $0.015–$0.125/GB-month $0.30/GB-month $0.023/GB-month
Use Case EC2-attached storage NFS for containers Data lakes

Explanation:

  • EBS: Low-latency block storage for EC2.
  • EFS: Shared file system for multiple instances.
  • S3: Durable object storage for backups/archives.

Detailed Explanations for Mastery

  • io2 Block Express:
    • Example: Provision io2 with 100,000 IOPS for SAP HANA.
    • Why It Matters: High performance—exam favorite.
  • Snapshot Encryption:
    • Example: Re-encrypt existing snapshot with new KMS key.
    • Why It Matters: Compliance—new for 2024.
  • Multi-Attach:
    • Example: Share io2 volume across 4 EC2 instances for Oracle RAC.
    • Why It Matters: Advanced HA—common scenario.

Quick Reference Table

Feature Purpose Key Detail Exam Relevance
Volume Types Optimize performance gp3, io2, st1, sc1 Core Concept
Snapshots Backup/restore Incremental, S3-based Core Concept
io2 Block Express Ultra-high performance 256,000 IOPS, 4,000 MB/s Performance
Cross-Region Disaster recovery Replicate snapshots Resilience
Encryption Security KMS, default for snapshots Security
Snapshot Archive Cost savings $0.0125/GB-month, slow restore Cost
Multi-Attach Shared storage io2/io1, 16 instances Flexibility
Fast Snapshot Restore Quick recovery Pre-initialized snapshots Resilience