Pass the AWS Certified Solutions Architect Associate Certification SAA-C03-(Episode 5: EC2 Instance Storage)
📌 Notice
Welcome to the series of blog in my AWS Certified Solutions Architect Associate (SAA-C03) exam preparation series! If you’re looking to pass this challenging yet rewarding certification, you’re in the right place.
Throughout this blog series, you’ll master core AWS architecture concepts — from IAM security fundamentals to advanced VPC networking, cost-optimized EC2 deployments, serverless patterns with Lambda, and multi-region disaster recovery strategies. We’ll break down all key services (S3, RDS, CloudFront etc.) through real-world solution architectures and exam-focused scenarios. Each post will include hands-on walkthroughs, pro tips for the SAA-C03 exam, and best practices used by AWS professionals. Get ready to transform from AWS beginner to certified Solutions Architect!
Note : The blog will be updated with the extra questions and CDK Implementation in a timely manner
🌟 Introduction
When working with Amazon EC2 (Elastic Compute Cloud), one of the key decisions you’ll make is choosing the appropriate storage for your workloads. Amazon offers three primary storage options: EBS (Elastic Block Store), EFS (Elastic File System), and EC2 Instance Store. Each has its own strengths, weaknesses, and ideal use cases.
This guide aims to break down these storage types in an easy to understand way using analogies, diagrams, and comparison tables, helping you choose the right solution for your architecture.
What is AMI ?
An AMI (Amazon Machine Image) is a pre-configured image used to launch EC2 instances. It includes own OS, application software, configurations, and can be shared or reused.
- AMI are a customization of an EC2 instance
- Faster boot / configuration time because all your software is pre-packaged
- AMI are built for a specific region (and can be copied across regions)
- You can launch EC2 instances from:
1. A Public AMI: AWS provided
2. Your own AMI: you make and maintain them yourself
3. An AWS Marketplace AMI: an AMI someone else made (and potentially sells)
AMI Process (from an EC2 instance)
- Start an EC2 instance and customize it
- Stop the instance (for data integrity)
- Build an AMI — this will also create EBS snapshots
- Launch instances from other AMIs
- Hands-On : Click Here
1. What is EBS (Elastic Block Store)?
EBS is a network-attached storage solution designed for persistence and reliability. Think of EBS as a “network USB stick” that can be detached and reattached to EC2 instances.
Key Features
- Persistent storage even after EC2 instance termination.
- Attached to only one instance at a time (except multi-attach volumes).
- Bound to a single Availability Zone (AZ).
- Backed by EBS Snapshots for backup and migration.
- Supports encryption using AWS KMS.
- Free tier: 30 GB of free EBS storage of type General Purpose (SSD) or
Magnetic per month
Example
- It’s a network drive (i.e. not a physical drive)
• It uses the network to communicate the instance, which means there might be a bit of latency
• It can be detached from an EC2 instance and attached to another one quickly - It’s locked to an Availability Zone (AZ)
• An EBS Volume in us-east-1a cannot be attached to us-east-1b
• To move a volume across, you first need to snapshot it - Have a provisioned capacity (size in GBs, and IOPS)
• You get billed for all the provisioned capacity
• You can increase the capacity of the drive over time
Delete on Termination attribute
- Controls the EBS behaviour when an EC2 instance terminates
- By default, the root EBS volume is deleted (attribute enabled)
- By default, any other attached EBS volume is not deleted (attribute disabled)
- This can be controlled by the AWS console / AWS CLI
Use case: preserve root volume when instance is terminated
EBS Snapshots
- Make a backup (snapshot) of your EBS volume at a point in time
- Not necessary to detach volume to do snapshot, but recommended
- Can copy snapshots across AZ or Region
EBS Snapshots Features
- Archive Tier: 75% cheaper but slow restore (24–72 hrs).
- Recycle Bin: Recover deleted snapshots within retention period (from 1 day to 1 year).
- Fast Snapshot Restore (FSR): Force full initialization of snapshot to have no latency on the first use ($$$)
EBS Multi-Attach — io1/io2 family
- Attach the same EBS volume to multiple EC2 instances in the same AZ (Up to 16 EC2 Instances at a time)
- Each instance has full read & write permissions to the high performance volume
EBS Encryption
BS Encryption protects your data at rest (on disk) and in transit (between EC2 and EBS) using AES-256 encryption, powered by AWS Key Management Service (KMS).
- When you create an encrypted EBS volume, you get the following:
• Data at rest is encrypted inside the volume
• All the data in flight moving between the instance and the volume is encrypted
• All snapshots are encrypted
• All volumes created from the snapshot - Encryption and decryption are handled transparently (you have nothing to do)
- Encryption has a minimal impact on latency
- Copying an unencrypted snapshot allows encryption
- Snapshots of encrypted volumes are encrypted
Encryption: encrypt an unencrypted EBS volume
- Create an EBS snapshot of the volume
- Encrypt the EBS snapshot ( using copy )
- Create new ebs volume from the snapshot ( the volume will also be
encrypted ) - Now you can attach the encrypted volume to the original instance
2. What is EC2 Instance Store?
EC2 Instance Store (also called ephemeral storage) is temporary, ultra-fast block storage physically attached to your EC2 instance. It’s ideal for data that doesn’t need to persist long-term.
- EBS volumes are network drives with good but “limited” performance
- If you need a high-performance hardware disk, use EC2 Instance
Store - Better I/O performance
- EC2 Instance Store lose their storage if they’re stopped (ephemeral)
- Good for buffer / cache / scratch data / temporary content
- Risk of data loss if hardware fails
- Backups and Replication are your responsibility
3. What is EFS (Elastic File System)?
Amazon EFS is a fully managed, scalable, shared file storage service for EC2 instances. It uses the NFS protocol (v4.1) and is designed for multi-AZ access, making it ideal for workloads requiring shared storage across multiple instances.
- Managed NFS (network file system) that can be mounted on many EC2
- EFS works with EC2 instances in multi-AZ
- Highly available, scalable, expensive (3x gp2), pay per use
- Use cases: content management, web serving, data sharing, Wordpress
- Uses NFSv4.1 protocol
- Uses security group to control access to EFS
- Compatible with Linux based AMI (not Windows)
- Encryption at rest using KMS
- POSIX file system (~Linux) that has a standard file API
- File system scales automatically, pay-per-use, no capacity planning!
Performance & Storage Classes
Storage Classes
EBS vs EFS vs Instance Store
AWS Hands-On
- AMI — Click Here
- EBS — Click Here
- EFS— Click Here
AWS Cloud Practitioner Questions
- EC2 Instance Storage — Click Here
AWS Solution Architect Associate Questions
- AWS SAA-C03 Sample Questions — Click Here
🧾 Conclusion
Amazon EBS provides persistent, high-performance block storage for single EC2 instances (ideal for databases/boot volumes), while Instance Store delivers ultra-fast temporary storage for ephemeral workloads (like caching). EFS, on the other hand, offers scalable shared file storage across multiple instances, perfect for multi-AZ applications. Choose EBS for durability, Instance Store for speed, and EFS for collaboration — each serving distinct needs in the AWS ecosystem while enabling hybrid architectures when combined.
- Need speed? → Instance Store
- Need durability? → EBS
- Need shared access? → EFS
How They Work Together
Hybrid Workload Example:
- Instance Store: Process temporary data (e.g., video transcoding).
- EBS: Store the final output persistently (e.g., in a database).
- EFS: Share input files across multiple instances (e.g., media files for rendering).
Key Takeaways
- EBS = Your “private hard drive” (persistent, single-instance).
- Instance Store = “RAM disk” (fastest, but temporary).
- EFS = “Shared network folder” (multi-instance, scalable).
Pro Tip: Use EBS for databases, Instance Store for scratch data, and EFS for team projects needing shared access!
Previous Episode : “Pass the AWS Certified Solutions Architect Associate Certification SAA-C03! (Episode 4: EC2 Solutions Architect Associate Level)”
Next Episode : “Pass the AWS Certified Solutions Architect Associate Certification SAA-C03! (Episode 6: High Availability & Scalability )”
