EC2 — Mount

Progress checklist

Connected to the instance via SSM Session Manager
amazon-efs-utils v3.0.0 or newer installed
Mount point /mnt/s3files created
File system mounted with mount -t s3files
/etc/fstab entry added for persistence across reboots

Overview

Run all commands in this page inside the SSM session on the EC2 instance. Start a session from your workstation if not already connected:

aws ssm start-session \
  --target "$INSTANCE_ID" \
  --region "$AWS_REGION"

Install amazon-efs-utils v3.0.0 or newer. Required

S3 Files requires the updated amazon-efs-utils package that ships with the s3files mount type support. Run on the instance:
Terminal window
```
sudo dnf install -y amazon-efs-utils
```
Confirm the installed version is 3.0.0 or newer:
Terminal window
```
rpm -q amazon-efs-utils
```
The mount -t s3files helper is only available in amazon-efs-utils v3.0.0+. Earlier versions ship with EFS-only support. If the dnf version is too old, update the package index first: sudo dnf update -y amazon-efs-utils.
Set the file system ID in the session. Required

Export FS_ID inside the SSM session so the mount command can reference it:
Terminal window
```
export FS_ID=fs-0123456789abcdef0   # ← replace with the ID from Setup
echo "FS_ID=$FS_ID"
```
Tip
Your FS_ID was printed during File System setup. If you have lost it, run the following on your workstation (not in the SSM session):
Terminal window
aws s3files list-file-systems \ --bucket "arn:aws:s3:::${BUCKET}" \ --region "$AWS_REGION" \ --query 'fileSystems[0].fileSystemId' \ --output text
Create the mount point. Required
Terminal window
```
sudo mkdir -p /mnt/s3files
```
Mount the file system. Required
Terminal window
```
sudo mount -t s3files "${FS_ID}:/" /mnt/s3files
```
The mount may take 10–30 seconds while the NFS connection is established with the mount target. If it hangs for more than 60 seconds, check that port 2049 TCP is open between the compute and mount target security groups (see Security Groups).

Allow the ssm-user to read the mount root without sudo:
Terminal window
```
sudo chmod 755 /mnt/s3files
```
Add a persistent fstab entry. Required

This ensures the file system remounts automatically after a reboot:
Terminal window
```
echo "${FS_ID}:/ /mnt/s3files s3files _netdev,noresvport 0 0" \
  | sudo tee -a /etc/fstab
```
Verify the entry was written correctly:
Terminal window
```
grep s3files /etc/fstab
```

Next step

Continue to Verify to confirm the mount and test read/write access.