Introduction
For over a decade, we’ve been known S3 is not a file system. We used hacks like s3fs-fuse or accepted the limited semantics of Mountpoint for S3. That has changed on April 2026.
AWS has launched a new S3 feature called S3 Files, a native capability that allows us to mount S3 buckets which under hood used AWS EFS (NFS v4.1+ with full POSIX semantics).
In this tutorial we’ll mount it to EC2, however there are other suppported services.
Demo
Lets see how to create and use S3 files with EC2 instanced.
Step 1: Creating Bucket and file system
Create a ‘General Purpose’ S3 bucket and turn on versioning, you can’t create file system if versioning is disabled.
Now click on the file systems tab
Change the bucket prefix or vpc if you want or proceed with the creation.
It would take a few mins to create the file system and mount targets, mount targets will be created in all the AZs of the particular region where the bucket is created.
Once the mount targets are available, we are ready to mount this. Now as you can see we can attach this to not only EC2 but Lambda and ECS tasks as well.
Note: Check the security group attached to these mount targets as we’ll need to edit it to allow NFS inbound rule. You can either allow 2049 from any source or allow only from the sg of the EC2 instance.
Step 2: Creating EC2 instance
Create an EC2 instance as usual but we must select a subnet to proceed otherwise S3 files can not be mounted.
Click add shared file system by choosing S3 in files option. You should see mount point and a command for later use. Copy and paste that somewhere.
Additionally you have to attach an IAM role to the instance with specific S3files policy, or attach existing policy of S3FilesClientFullAccess. Check the documentation for more info
Step 3: Mounting S3 file system
SSH to your machine, and run the command copied earlier. Make sure to update the system cache and have curl installed if not already present.
curl https://amazon-efs-utils.aws.com/efs-utils-installer.sh | sh -s -- --install-launch-wizard \
--mount-s3files fs-0d8949dde025cba67 /mnt/s3/fs1
If you see any permission errors, it could be misconfigured IAM role or the inbound port of the security group attached to S3 does not have FNS rule.
When all the permission are sorted (if any) the mounting will be successful. And you can view and list the mount point.
You can now create file in that particular mount point and the files will be visible in S3 bucket or upload files in S3 bucket and the same will be available inside the instance.
Wrap up
Amazon S3 Files marks a major turning point by providing native NFS v4.1+ support and full POSIX semantics directly on your buckets. For a deeper dive into the technical setup and implementation details, be sure to explore the official documentation and the launch announcement linked below.