Task Statement 3.1: Determine high-performing and/or scalable storage solutions.
📘AWS Certified Solutions Architect – (SAA-C03)
1. Storage Types Overview (VERY IMPORTANT)
Before learning services, understand three storage types:
1. Object Storage
- Stores data as objects (files + metadata)
- Accessed via HTTP/HTTPS (API calls)
- Highly scalable
👉 Used by: Amazon S3
2. Block Storage
- Stores data as blocks (like a hard disk)
- Attached to EC2 instances
- High performance, low latency
👉 Used by: Amazon EBS
3. File Storage
- Stores data in files and folders (like shared drives)
- Supports multiple users/instances
👉 Used by: Amazon EFS
2. Amazon S3 (Object Storage)
Key Features
- Unlimited storage
- 99.999999999% durability (11 9’s)
- Accessible from anywhere via internet
- Automatically scales
- Stores unstructured data
Storage Classes (Exam Favorite)
Different classes based on access frequency:
- S3 Standard → Frequent access
- S3 Intelligent-Tiering → Automatic cost optimization
- S3 Standard-IA → Infrequent access
- S3 One Zone-IA → Single AZ, cheaper
- S3 Glacier Instant Retrieval
- S3 Glacier Flexible Retrieval
- S3 Glacier Deep Archive
Use Cases
Use S3 when you need:
- Static website hosting
- Backup and restore
- Data lakes / big data storage
- Log storage (CloudTrail, ELB logs)
- Media files (images, videos)
- Disaster recovery storage
Important Exam Points
- Data is stored in buckets
- Not attached to EC2
- Supports event notifications
- Lifecycle policies for automatic tiering
- Versioning for data protection
- Cross-Region Replication (CRR)
When to Choose S3
Choose S3 if:
- You need massive scalability
- You don’t need a file system or disk
- Data is accessed via API or web
3. Amazon EBS (Block Storage)
Key Features
- Persistent storage for EC2
- Acts like a hard disk
- Low latency, high performance
- Data stored within a single Availability Zone
Volume Types (Exam Critical)
SSD (for performance)
- gp3 / gp2 → General purpose
- io1 / io2 → High-performance, mission-critical
HDD (for throughput)
- st1 → Throughput optimized
- sc1 → Cold storage (low cost)
Use Cases
Use EBS when you need:
- Operating system (boot volume)
- Databases (MySQL, PostgreSQL)
- Transaction-heavy applications
- Applications requiring low latency
Important Exam Points
- Attached to one EC2 instance at a time (except Multi-Attach for io1/io2)
- AZ-specific (not region-wide)
- Snapshots stored in S3
- Can increase size without downtime
- Supports encryption
When to Choose EBS
Choose EBS if:
- You need high-performance disk
- Data must be accessed quickly
- You run databases or OS-level apps
4. Amazon EFS (File Storage)
Key Features
- Fully managed file system
- Supports multiple EC2 instances
- Automatically scales
- Uses NFS protocol
Performance Modes
- General Purpose → Low latency
- Max I/O → Higher throughput
Throughput Modes
- Bursting
- Provisioned
- Elastic (new)
Use Cases
Use EFS when you need:
- Shared file storage across multiple EC2 instances
- Web servers sharing files
- Container storage (ECS, EKS)
- Content management systems
Important Exam Points
- Works across multiple AZs
- Highly available and scalable
- More expensive than EBS
- Linux-based workloads (NFS)
When to Choose EFS
Choose EFS if:
- Multiple EC2 instances need shared access
- You need a file system (not disk or object)
5. Quick Comparison (VERY IMPORTANT FOR EXAM)
| Feature | S3 | EBS | EFS |
|---|---|---|---|
| Type | Object storage | Block storage | File storage |
| Scalability | Unlimited | Limited to volume size | Automatic scaling |
| Access | API / HTTP | Attached to EC2 | Mounted (NFS) |
| Multi-instance | Yes | No (mostly) | Yes |
| AZ Scope | Regional | Single AZ | Multi-AZ |
| Performance | Moderate | Very high | High |
| Use Case | Backup, static files | Databases, OS | Shared file systems |
6. Decision Guide (Exam Logic)
Choose S3 if:
- Data is static or unstructured
- Needs internet access
- Requires unlimited scale
Choose EBS if:
- You need a disk attached to EC2
- Running databases or OS
- Require low latency
Choose EFS if:
- Multiple EC2 instances need access
- Need a shared file system
- Want automatic scaling
7. Common Exam Scenarios
Scenario 1
Application stores images and videos with high durability
👉 Answer: Amazon S3
Scenario 2
Database running on EC2 requires low latency
👉 Answer: Amazon EBS
Scenario 3
Multiple EC2 instances need shared storage
👉 Answer: Amazon EFS
Scenario 4
Backup solution with lifecycle policies
👉 Answer: Amazon S3
8. Common Mistakes (VERY IMPORTANT)
- ❌ Using EBS for shared storage → Use EFS instead
- ❌ Using S3 as a file system → It is object storage
- ❌ Forgetting EBS is AZ-specific
- ❌ Assuming EFS works like block storage (it does NOT)
9. Final Exam Tips
- Always identify:
- Access pattern (single vs multiple instances)
- Performance requirement
- Storage type (object, block, file)
- Remember this shortcut:
👉 S3 = scalable object storage
👉 EBS = EC2 disk
👉 EFS = shared file system
