# Ensure Mounting FSx Cache

- Source: https://support.icompaas.com/support/solutions/articles/62000234553-ensure-mounting-fsx-cache
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [CIS AWS Storage Services Benchmarks v1.0.0](https://support.icompaas.com/support/solutions/62000112689) › [CIS AWS Storage Services](https://support.icompaas.com/support/solutions/folders/62000169254)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

Profile Applicability:

-   **Level 2**

### Description:

Amazon FSx provides fully managed file systems for Windows and Lustre. Ensuring that FSx cache is properly mounted on instances is important for applications that require high-performance storage. Mounting the FSx cache ensures that your file systems are accessible and can be used for processing data or serving files to applications.

### Rationale:

Mounting FSx cache ensures:

-   Access to fast, temporary storage for data processing  
    
-   High performance with minimal latency for file system operations  
    
-   Integration with applications that require distributed file systems  
    
-   Cost-effective use of cache for applications that process large datasets  
    

### Default Value:

By default, FSx file systems are not mounted on EC2 instances. You must manually mount the cache to the instances for use.

### Impact:

Pros:  
 • Provides fast, low-latency access to temporary data  
• Supports high-performance applications that require shared storage  
 • Easy integration with AWS services for data processing

Cons:  
 • Misconfigured or missing mounts may lead to application errors  
• Requires manual setup and monitoring for availability  
 • Can lead to higher costs if not cleaned up properly after us

### Pre-requisites:

IAM Permissions Required: fsx:DescribeFileSystems, fsx:DescribeMountTargets, ec2:DescribeInstances, ec2:AttachVolume, ec2:RunInstances  
 Access to FSx file systems and EC2 instances

### Remediation:

### Test Plan:

Using AWS Console:  
 • Log in to the AWS Management Console  
 • Navigate to FSx > File systems  
 • Select the FSx file system you want to mount  
 • Go to the Mount targets section and identify the target IP address for mounting  
• SSH into your EC2 instance  
• Ensure the correct mount command is used to mount the cache on the instance  
 • Confirm that the mount is successful and accessible by running file system operations

Using AWS CLI:

aws fsx describe-file-systems \\
  --file-system-id fs-xxxxxxxxxxxxxxxxx
aws fsx describe-mount-targets \\
  --file-system-id fs-xxxxxxxxxxxxxxxxx

### Implementation Plan:

Using AWS Console:  
 • Navigate to FSx > File systems  
 • Select the File system you want to mount  
 • Under the Mount targets section, copy the Mount target IP address  
 • SSH into the EC2 instance where the file system will be mounted  
 • Run the mount command (for Linux)

sudo mount -t nfs -o nfsvers=4.1 <mount-target-ip>:/ fsx-mount

• For Windows, use the mount network drive functionality  
 • Confirm access by checking the mount on the instance

Using AWS CLI:  
 Step 1: List the FSx mount targets

aws fsx describe-mount-targets \\
  --file-system-id fs-xxxxxxxxxxxxxxxxx

Step 2: Mount the file system (Linux example)

sudo mount -t nfs -o nfsvers=4.1 <mount-target-ip>:/ fsx-mount

Step 3: Verify the mount

df -h

Step 4: For Windows, use the net use command to mount:

net use Z: \\\\<mount-target-ip>\\<share-name>

### Backout Plan:

Using AWS Console:  
 • Unmount the FSx file system from the EC2 instance  
 • Navigate to FSx > Mount targets and disassociate any unnecessary targets  
 • If data was accidentally written to a temporary mount, verify that data is backed up before unmounting

Using AWS CLI:

sudo umount fsx-mount

For Windows, unmount:

nt use Z: /delete

### References:

-   [https://docs.aws.amazon.com/fsx/latest/LustreGuide/mounting.html](https://docs.aws.amazon.com/fsx/latest/LustreGuide/mounting.html)
-    [https://docs.aws.amazon.com/cli/latest/reference/fsx/](https://docs.aws.amazon.com/cli/latest/reference/fsx/)
-    [https://aws.amazon.com/fsx/](https://aws.amazon.com/fsx/)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.