Amazon EFS: The storage missing link?

by | Jun 30, 2016 | Blog

It’s been a long time coming, but Amazon EFS is now generally available!

EFS joins EBS and S3 as storage options for your AWS environment. Now that’s a lot for acronyms in one sentence, so lets do a high level recap of what they all mean:

What does it stand for? Elastic Block Store.
What is it? Persistent block level storage for Amazon EC2 instances. Available in SSD and HDD depending on your performance requirements.
What would I use it for? EBS is basically a cloud based SAN, which you use to mount storage volumes to your EC2 instances so you can run your operating systems, databases, web servers, application servers, etc.
What does it cost? Between $0.025-$0.125 per GB depending on the type of storage class.

What does it stand for? Simple Storage Service.
What is it? Online object storage for files and folders that is accessible from anywhere. Available in a variety of storage classes depending on your access requirements.
What would I use it for? S3 is like Dropbox (in fact Dropbox used to run on S3) that you can use to store and archive your files, images, videos, backups, etc. You can also run static websites from Amazon S3.
What does it cost?
Between $0.007-$0.030 per GB depending on the type of storage class.

What does it stand for? Elastic File System.
What is it? Elastic storage for Amazon EC2 instances that can grow and shrink automatically as you add and remove files AND it can be accessed by multiple EC2 instances at the same time.
What would I use it for? EFS is the AWS version of NFS, as it’s mountable on multiple EC2 instances at the same time, so you would use it as a common data source for applications running on more than one Amazon EC2 instance.
What does it cost?
Between $0.30-$0.33 per GB depending on the region.

EFS plugs the gaps in the EBS and S3 services, albeit at a much, much higher cost.

The following table summarizes the key differences between each of the services:


This is a big step forward for AWS as the unavailability of an NFS type service has long been a complaint.

The EFS file system creation process is very simple and AWS spoon feeds you all the commands to run. In just a couple of minutes I had an EFS file system attached to two of my EC2 Linux instances and was able to share files between them. Also I was quite impressed with the amount of disk space at my disposal (around 9000 Petabytes!)


So that’s Linux/Unix sorted. Great! Now it’s time to test EFS on Windows, oh hang on…

Amazon EFS supports both NFSv4.1 and NFSv4.0, but crucially does not support NFSv2, or NFSv3. What does this mean in English? Well natively Windows does not support NFSv4.0 and if you scroll down the Amazon EFS  documentation page you see the following:


Aaargh, so Amazon EFS isn’t quite yet the storage silver bullet! But at least it’s a big step in right direction!

To streamline your migration to AWS, just email me at