Storage that Scales: EFS vs. EBS vs. Zesty Disk

Read More >

Shopping for a solution for your application storage can be confusing to say the least. With so many options available, it’s difficult to know which storage options will provide the greatest stability and performance for your particular application.

That’s why we’re offering this quick and simple guide which will help you decipher the benefits and drawbacks of AWS EFS and how it compares to EBS and Zesty Disk – our very own autoscaling storage solution.

Let’s get started!

What is AWS EFS?

Amazon Elastic File System (EFS) is a fully managed file storage service that provides a shared elastic file system and can automatically shrink and extend the capacity based on usage. EFS provides Network File System (NFS) file systems and in its basic configuration, performance is linked to utilization, but this depends on the usage tier chosen.

EFS can be used as a common datasource for any application or workload that runs on numerous instances. Using an EFS file system, you can configure multiple instances to mount the file system at the same time, with a throughput limitation of 1-3 GiB/s in most AWS regions.

In its basic configuration, an EFS file system is spanned over 3 AWS availability zones (AZs), meaning you get high availability by design. Since EFS serves an NFS file system and its connectivity is based on TCP networking; the latency you get from the file system may vary.

What is AWS EBS?

AWS Elastic Block Storage (EBS) solution, is a block storage technology that is used to store data on EC2 instances and additional managed services for situations that require low latency, efficiency, and reliability. EBS infrastructure is based on an internal AWS network that provides single-digit ms latency. The network is built on AWS EBS Nitro card which allows I/O offloading to the cards.

With EBS volumes, the Operating system (OS) stores storage blocks using SCSI commands which act as separate hard drives. As a result, block storage devices are flexible and offer high performance when compared to regular file storage.

EBS volumes are spanned over two Availability Zones (AZs) meaning you get only two copies of each volume.

EBS volumes are the most common choice for running databases and hosted applications – whether they are on a regular operating system or running as a container.

There are 5 types of Solid State Disk (SSD) EBS volumes: General Purpose – GP2, GP3, Io1, Io2, Io2 block express, and 2 types of Hard Drive Disks (HDD) – SC1 and ST1.

There is an additional AWS service called FSx which provides more options for managed file systems solutions like Windows File server, FSx for Lustre, OpenZFS and NetApp. We will discuss this service in a future post.

In the meantime, AWS offers a great comparison between various EBS volume types, which can be found in their documentation.

What is Zesty Disk?

Zesty Disk is the first block storage autoscaler that automatically shrinks and expands EBS volumes according to real-time application demand. This way, engineers never need to overprovision volumes or manually adjust storage capacity. Zesty Disk continuously adjusts EBS volumes in real-time, ensuring applications always run at optimum performance and stability, while saving users up to 70% on EBS maintenance and costs.

AWS EFS vs. AWS EBS: Which one should you use?

While both EBS and EFS offer great features, these two storage solutions are actually built for two completely different use cases. ​​EBS volumes are limited to a single instance, unless you utilize the “multi-attach EBS volumes” feature, which was designed to support Windows clusters. With EFS, you can have up to 400 instances accessing the file system simultaneously. This makes AWS EFS a great fit for any use case that requires centralized shared file storage, uses like media processing, or shared code repositories.

Why do customers choose EFS over EBS?

  1. When conducting a lift-and-shift migration from on-premise datacenter file storage (Like Netapp for example) to AWS. The evolution of such a migration is to move the files to S3 which is a more scalable and cost-effective solution.
  2. When an application requires a shared file system that is not I/O sensitive and requires POSIX compliance (so it can provide file permissions, for example).
  3. When a customer’s AWS knowledge is limited. Everyone knows Linux, NFS and EFS – so it feels like the safest choice for a shared file system in a Linux environment.

On the surface, AWS EFS sounds like a simple service and can be very beneficial in some cases, but it can also have significant drawbacks. For example, you might not have high enough utilization to reach the desired throughput of the file system.

Therefore, because AWS EBS provides you with steady and predictable performance, EBS is almost always a better fit, unless you have a specific use case such as accessing files that are stored in a central repository, which is ideal for EFS.

EBS is leveraged for many use cases including running Databases on EC2 or RDS or running applications which require storage volumes with decent response times.

Another important aspect is cost.

In some scenarios, EFS will be more costly (often reaching 4-5x the cost of a comparable EBS deployment). Part of this will depend on whether you are using MAx Throughput mode which requires you to utilize a large amount of capacity in order to achieve a high level of IOPS.

With EBS, once a volume is provisioned, you know exactly how much IOPS you will get no matter what volume type you use (GP2, GP3, Io1 or Io2). In many cases, your volumes are over-provisioned and not maintained at all, which can cause a huge headache to the DevOps, FinOps and finance teams once they discover that EBS is a significant portion of their AWS bill.

So how does Zesty Disk combat this challenge?

If you’re looking to get the most flexibility and cost-efficiency out of EBS, Zesty Disk is the ideal solution.

Zesty Disk automatically increases and decreases storage volumes in real-time, based on the application’s needs using our unique AI algorithms.

In essence, it’s automated real-time right-sizing of your storage volumes, which eliminates any need to manually manage your storage infrastructure.

In addition, the ability to provide multiple channels for read/write operations, achieves improved performance when compared to out-of-the-box EBS.


The diagram below is an example of an EBS volume that is managed by Zesty Disk. As you can see, the behavior of this volume looks very similar to a classic EC2 auto-scaling solution, where the Compute will scale according to the load’s requirements.

However, here we can see that instead of scaling EC2 instances, we are scaling the capacity of the storage volumes up and down as the usage fluctuates in real-time, while ensuring that the required performance is being kept.

For more information, check out our side-by-side comparison of EFS, EBS, and Zesty Disk below:

A Quick Comparison of AWS EFS, EBS and Zesty Disk

Choosing the right storage option for your application will have significant implications on how smooth your application functions, as well as its costs. While EFS offers benefits such as high availability, its latency may vary and in many cases, it tends to cost 4-5 times more than a comparable EBS deployment. In contrast, EBS, a more popular and robust block storage solution, offers a high level of availability, flexibility, and performance, making it more suitable for a larger variety of use cases. The drawback is its lack of predictability, which has significant cost repercussions.

Zesty Disk takes EBS to the next level. You get all the benefits of out-of-the-box EBS, along with innovative shrink and expand technology that ensures your disk is always optimized to your real-time application requirements without any human intervention. In addition, Zesty Disk increases EBS’s performance by providing multiple channels for read/write operations.

Play Video

Want to see for yourself how Zesty Disk can extend your disk’s capabilities with zero effort on your end? Contact one of our cloud experts to learn more!