How to Choose the Right AWS Storage Solution for your Project - S3, EFS, EBS or RDS

Object Storage vs File System vs Block Storage. Understanding the Differences


Ah, the age-old question: S3, EFS, EBS, or RDS - which one should I choose for my shiny new project? As a software developer, I know that choosing the right storage solution can be a bit like trying to pick the perfect avocado at the grocery store. They all look similar on the outside, but once you dive in, you realize that each one is uniquely suited for different tasks.

In this article, I hope to demystify the world of AWS storage and make it easier for you to choose the right service for your project.

Amazon S3

Let's start with S3 or Simple Storage Service. S3 is an object storage service, which means it stores data in the form of "objects" that are stored in a flat structure, consisting of a file and its associated metadata. This type of storage is different from traditional file systems and data blocks because it uses a different method for organizing and accessing data.

In an object storage type of system, each object is given a unique identifier and can be accessed directly, without the need to navigate through a directory structure, kind of like a key-value type of storage.

S3 is perfect for storing large amounts of unstructured data, like images, videos, and backups. It's also highly scalable, so you can store an almost unlimited amount of data and easily add more storage as your needs grow. S3 also offers built-in redundancy and data durability. But be careful, S3 isn't the best option for storing Online Transactional Processing (OLTP) type of data, because it's not intended for use as a database.

Amazon Elastic File System (EFS)

Next up, we have EFS or Elastic File System. EFS is a file storage service, that stores data in the form of a file system, with directories and files and can be accessed by multiple EC2 instances at the same time.

In a file system, data is organized into a hierarchical structure, with files and folders being stored on a hard drive or another storage device.

You can think of a file system as a tree, where each file and folder is represented as a node in the tree, and the relationships between them are represented by the parent-child relationships between the nodes. To access a specific file, the file system's software must navigate through the directory structure to find the file, following the parent-child relationships between the nodes.

EFS is best suited for use cases where you need to store and access large amounts of data across multiple instances, such as a shared file system for a group of web servers. EFS is a great choice for applications that require a file system, such as storing application data or home directories for users. However, EFS does not have the same scalability as S3, and it can be more expensive for storing large amounts of data.

Amazon Elastic Block Store (EBS)

EBS or Elastic Block Store is a block storage service that is best suited for use with Amazon Elastic Compute Cloud (EC2) instances. It allows you to create storage volumes and attach them to EC2 instances, providing persistent storage for your applications.

Block Storage it's similar to a traditional hard drive and stores data in the form of blocks that are treated as individual, discrete units.

You can think of block storage as a digital version of a filing cabinet. Each "block" is like a separate file folder in the cabinet, and you can add, remove, or change the contents of any individual folder without affecting the other folders.

Unlike S3 and EFS, you can also take snapshots of your EBS volume, enabling you to back up and restore your data easily. But, EBS is limited to a specific availability zone, which means it's not as durable as S3.

Amazon Relational Database Service (RDS)

Lastly, we have RDS or Relational Database Service. RDS is a managed service that makes it easy to set up and operate a relational database, such as MySQL or PostgreSQL. RDS is also a block storage service.

RDS is a great choice for applications that need a relational database, such as e-commerce websites or social media platforms. RDS offers automatic backups, software updates, and the ability to scale storage and compute resources as needed. However, these features come with costs, RDS can be more expensive than running a database on a traditional EC2 instance with an EBS volume attached to it.


In summary, S3 is best for storing large amounts of unstructured data, EFS is best for file storage and file system operations, EBS is best for low-latency high-throughput data access, and RDS is best for relational databases. It's important to evaluate your specific use case and choose the service that best fits your needs.

So, when should you use S3 vs EFS vs EBS vs RDS?

  • Use S3 if you need to store large amounts of unstructured data and don't need a file system.

  • Use EFS if you need a file system and support for file system operations.

  • Use EBS if you need low-latency, high-throughput data access attached to a single EC2 instance, like databases and virtualization.

  • Use RDS if you need a relational database and the managed service features it offers.

I hope this article has helped demystify the world of AWS storage and made it easier for you to choose the right service for your project.