AWS Storage Options: Amazon S3, Glacier, EBS, EFS

The portfolio of AWS storage products offers a multitude of options for each and every usage scenario. Navigating through them may prove troublesome for inexperienced users, as each storage class is crammed with many specificities that have to be considered. In this article we set out to clarify the use-cases of the following AWS storage classes: Amazon EBS, EFS, S3, and Glacier.

Introduction to Amazon Storage: Handle the Abundance of Options

Data is slowly but surely moving to the cloud. Pervasive accessibility, durability, and flexible costs make the decision on cloudization a no-brainer. Naturally, the abundant selection of cloud storage services and storage classes make it a bit difficult to land your mind on something particular. Although, in all honesty, it’s actually not that hard to wrap your mind around these concepts. In the following paragraphs we will succinctly explain the nature of four main AWS cloud storage classes, their application within your future cloud infrastructure, and also how to ensure that your data is ever intact and robustly secure.

AWS Storage: S3 (Simple Storage Solution)

Think of Amazon S3 as a cloud storage intended to interact with the outer world. It is in fact a static storage service that is best suited for website hosting, media distribution, and storing backups that might require immediate retrieval from the cloud. For instance, our website is stored on Amazon S3; so if you’re reading this, just know that this very sentence was fetched from S3. Similarly, Netflix uses Amazon S3 to stream their infinite library of movies and TV Shows to their subscribers. In other words, whenever you watch an episode of House of Cards, the data is being streamed straight from an S3 server. Another common scenario for using S3 is backups. Needless to say, backing up the most critical data is crucial for any organization as per the industry’s best practices. S3 is perfect for backups of any size and volume, providing high transfer speeds, encryption, compression, and a whole range of other useful features. Here’s a diagram that illustrates the most common application of Amazon S3:

Amazon S3 use cases

As you can deduce, S3 can best be characterized as a cloud storage offering high performance at massive scale. If you need a place to store your website, your backups, and other types of oft-accessed data, S3 is unquestionably your best option. In our own experience, Amazon S3 dwarfs its competitors when it comes to functionality, scalability, and stability. Now let’s move over to the S3’s brother — Amazon Glacier.

AWS S3 Standard Infrequent Access

Amazon S3 Standard - Infrequent Access (Standard - IA) is an Amazon S3 storage class for data that is accessed less frequently, but requires rapid access when needed. The data retrieval process starts within milliseconds upon request, as opposed to Glacier’s delays ranging from minutes to hours. Standard - IA offers the high durability, throughput, and low latency of Amazon S3 Standard, with a low per GB storage price and per GB retrieval fee. This combination of low cost and high performance make Standard - IA ideal for long-term storage, backups, and as a data store for disaster recovery. With regard to use-cases and pricing, Standard-IA appears to be somewhere between Standard S3 and Amazon Glacier. While Standard-IA provides the same availability as S3, it does charge you retrieval fees due to its backup-oriented nature.

AWS S3 One Zone-Standard Infrequent Access

In April 2018 AWS announced Amazon Simple Storage Service (Amazon S3) One Zone-Infrequent Access (Z-IA), that stores objects in a single Availability Zone. New storage class is designed for customers who want a lower-cost option for infrequently accessed data, but do not require the multiple Availability Zone data resilience model of the S3 Standard and S3 Standard-IA storage classes.

AWS S3 Glacier

Sometimes you need to store a library of old files that you rarely access but nonetheless consider to be critical and worthy of retaining. In the old days, people used to gather tons of paperwork and place them on the upper shelves in some dusty archive. And that’s pretty much what Amazon Glacier is — a cloud archive that stores your rarely-accessed files at a lower cost than S3. If you want to get rid of an army of tape or hard drives that contain your century-old data, it might make sense to offload that information to Amazon Glacier.

It would be utterly incorrect to directly compare Glacier to S3, as they in many cases complete each other rather than compete with each other. Whereas S3 can be conveniently employed as a storage for a website, user content, and regular backups, Glacier acts as a complimentary service that will store your rarely-accessed data at a sweet price. In fact, Amazon provides the so-called lifecycle policies that enable you to perform flexible and convenient data transfer between S3 and Glacier. Some say, that there are big differences between these two ways of upload. There are some, indeed. We will recommend S3-Glacier as a more convenient way.

In the olden days, Glacier retrieval was difficult to understand, long and expensive. Nowadays, it is only expensive. There are several retrieval tiers of how you can extract your files from this Cold storage. They all differ in terms of prices and, most importantly, time that should be taken to redeem your files. If you want to know more about that, please check out our article on new retrieval options of Amazon Glacier.

This table illustrates the pricing design behind the aforementioned AWS storage classes: the retrieval fees grow inversely with the storage fees. And finally here's a more comprehensive table that demonstrates the main differences between the AWS S3, Standard-IA, and Glacier:

S3Standard-IA / Standard Z-IAGlacier
Storage PricingHighMediumLow
Retrieval pricingNoneMediumHigh
Data access frequency (recommended)DailyOnce every two months or rarerOnce a year

You can find detailed prices in the official AWS Calculator.

AWS S3 Reduced Redundancy Storage

Amazon Reduced Redundancy Storage (RRS) is a bit of an outlier in the family of AWS storage classes. It's essentially an option that enables you to store noncritical, reproducible data at lower levels of redundancy than Amazon S3’s standard storage. While Amazon S3, Standard-IA, and Glacier provide the what's called "eleven nines" durability (99.999999999%), Amazon RRS provides you with a healthy but somewhat inferior 99.99% durability. However, it's actually a bit more expensive than S3 ($0.023 vs $0.024), so it truly makes no sense to utilize this storage class whatsoever — who needs lower durability and higher prices? The explanation for this peculiarity is the following: Amazon seems to be phasing out RRS in favor of S3, Standard-IA, and Glacier. So just forget that RRS ever existed!

By now we've covered all storage classes designed to interact with the outer world. If you'd like to dive deeper into the subject matter, feel free to head over to one of our articles that breaks everything down more comprehensively.

AWS Storage: EBS (Elastic Block Storage)

Amazon AWS offers a myriad of various services, ranging from virtual cloud compute capacity to the Internet-of-Things tools. As the scope of their services expanded, there was demand for a type of storage that acts as an auxiliary to their virtual cloud compute service — Amazon EC2. Amazon Elastic Cloud Compute (EC2) is essentially a web service that provides secure, resizable compute capacity in the cloud. EC2 enables you to request the so-called instances, which are basically cloud computers running Linux or Windows with dedicated computational capacity. Needless to say, computers hardly have any use without storage. That’s why Amazon EBS was brought into being. Amazon Elastic Block Store (Amazon EBS) provides persistent block storage volumes for use with Amazon EC2 instances in the AWS Cloud. Each Amazon EBS volume is automatically replicated within its Availability Zone to protect you from component failure, offering high availability and durability. Amazon EBS volumes offer the consistent and low-latency performance needed to run your workloads. In short, Amazon EBS goes hand in hand with EC2, so think of this storage class as an EC2’s auxiliary and not a standalone service. In fact, it's impossible to create an EC2 instance without an EBS volume, as the would-be operating system and data have to be stored somewhere. Here's the storage selection step when creating an EC2 instance:

Adding storage to EC2 instance

AWS Storage: EFS (Elastic File Storage)

Just as Amazon S3 is frequently compared to Glacier, the Amazon EBS is in the same vein repeatedly put against Amazon EFS — Amazon Elastic File System. Amazon EFS provides simple, scalable file storage for use with Amazon EC2 instances in the AWS Cloud. Amazon EFS is easy to use and offers a simple interface that allows you to create and configure file systems quickly and easily. With Amazon EFS, storage capacity is elastic, growing and shrinking automatically as you add and remove files, so your applications have the storage they need, when they need it.

The idea behind creating Amazon EFS was the following: many AWS customers required a way to more easily manage file storage on a scalable basis. Some of these customers run farms of web servers or content management systems that benefit from a common namespace and easy access to a corporate or departmental file hierarchy. EFS is excellent as a managed network file system wherein the file system can be shared across different EC2 instances.

EFS works like NAS devices and works well for big data analytics, media processing workflows, and content management.

EFS can be mounted to a multitude of AWS services, making it a splendid choice for a file system for all your EC2 instances performing various tasks — ranging from running a server to analysing Big Data. In essence, it’s better to think of EFS as a filesystem that can be mounted pervasively — something considerably more global in AWS terms compared with persistent block storage (EBS) intended for a single EC2 instance. Just take a look at the vastness of AWS and the potential application of EFS:

Amazon products proud list

We shall reiterate again that a more appropriate way to think of EFS is as of a complementary auxiliary to EBS. Whereas EFS serves as a network file share across the AWS line-up, EBS serves as an assistant storage for EC2 instances. It goes without saying that EFS comes at a higher price due to its superior functionality:



Storage (per GB-month)

$0.025 — $0.125*

$0.3 — $0.36*

Storage size

Up to 16 TB



Very High


Common usage

Interactive Applications (databases)

Big Data analysis

*the prices are set for April 2018. Please check out original prices with this official AWS Calculator

The pricing accurately reflects the scope of application and available functionality of both storage classes. Now that we've covered the basics of AWS storage classes, let's proceed to examine how you can leverage Amazon's cloud infrastructure to ensure that your most sensitive and critical data is intact and insusceptible to any malicious activity.

Which Storage Options are Supported in CloudBerry Backup?

CloudBerry Backup is a cross-platform backup solution that aims to keep up-to-date with the latest industry developments. With that in mind, we've ensured that flagship backup solution supports most cloud storage services, including the Amazon's lineup of storage classes. Namely, you can back up your files to both S3 and Glacier right within our app by simply indicating the backup destination and optionally enabling scheduling, compression, and 256-bit encryption.

Choose backup destination

Our comprehensive Backup Wizard similarly enables you to optionally store your files on Amazon's servers under the Standard-IA storage class.

Specify AWS storage class

And with the help of CloudBerry Explorer you can alter the storage class for any of your files in the cloud by simply selecting and deselecting checkboxes within the app's settings.

Changing storage class

Restoring Image-Based Backups to EC2 & EBS

Apart from backing up individual files, CloudBerry Backup allows you to perform image-based backups. Similarly, you can restore said image-based backups as an EC2 instance, Amazon Machine image, or a mere EBS volume.

Restoring to EC2 EBS

Where to go from here?

We've by now explained the ins and outs of various Amazon storage classes. Naturally, going into depth on each of them would require hundreds of paragraphs of complex wording, which would defeat the goal of this piece — to introduce you to the world of AWS storage classes. If you want to familiarize yourself with Amazon's vast universe of cloud services, we strongly suggest you head over to their comprehensive documentation that goes at length on everything they have to offer for your business with regard to cloud computing.