# Ensure /tmp Directory is Mounted on a Separate Partition

- Source: https://support.icompaas.com/support/solutions/articles/62000234914-ensure-tmp-directory-is-mounted-on-a-separate-partition
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [CIS Amazon Linux 2 Benchmark v3.0.0](https://support.icompaas.com/support/solutions/62000112696) › [CIS Amazon Linux 2 Benchmarks](https://support.icompaas.com/support/solutions/folders/62000169265)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**Profile Applicability:** • Level 1

**Description:**  
 The /tmp directory is used for temporary files by system and user applications. Mounting /tmp on a separate partition isolates temporary files from the root filesystem, improving security and stability.

**Rationale:** Having /tmp on a separate partition limits the impact of denial-of-service attacks, prevents temporary file exhaustion affecting other filesystems, and allows for specific mount options (e.g., noexec, nosuid) to be applied, reducing security risks.

**Impact:** Pros:

-   Limits damage caused by rogue or malformed temporary files.  
    
-   Allows enforcing stricter mount options for better security.  
    
-   Prevents /tmp from filling the root filesystem.
    

Cons:

-   Requires partitioning and potentially additional disk space allocation.  
    
-   Misconfiguration may cause system startup issues.  
    

**Default Value:** By default, /tmp is often part of the root filesystem and not a separate partition.

**Pre-requisites:**

-   Root or sudo privileges to modify disk partitions and /etc/fstab.  
    
-   Backup of critical data before repartitioning  
    

**Remediation:**

### **Test Plan:**

**Using Linux command line:**

1.  Check current mount points:  
    
    mount | grep /tmp
    
2.  Verify /tmp is mounted on a separate partition:  
    
     findmnt /tmp
    
3.  Check /etc/fstab for /tmp entry:
    
     grep /tmp /etc/fstab
    
    Expected output: /tmp should be listed as a separate mount point with appropriate options.
    

  

### **Implementation Plan:**

**Using Linux command line:**

1.  Create a separate partition or logical volume for /tmp (using tools like fdisk, lvcreate).  
    
2.  Format the new partition:  
    
     mkfs.ext4 /dev/<partition>
    
3.  Backup current /tmp contents:  
    
     cp -a /tmp /tmp\_backup
    
4.  Mount the new partition temporarily:  
    
     mount /dev/<partition> /mnt
    
5.  Copy back the contents:  
    
     cp -a /tmp\_backup/\* /mnt/
    

6.  Unmount temporary mount:  
    
     umount /mnt
    
7.  Mount /tmp:  
    
     mount /tmp
    
      
    
8.  Verify mount and permissions.  
    

### **Backout Plan:**

**Using Linux command line:**

1.  Remove or comment out the /tmp entry in /etc/fstab.  
    
2.  Unmount /tmp:  
    
     umount /tmp
    
      
    
3.  Restore original /tmp contents if needed:
    
     cp -a /tmp\_backup/\* /tmp/
    
4.  Reboot system or remount root filesystem.  
    

**References:**

-   CIS Amazon Linux 2 Benchmark v3.0.0  
    
-   [NIST SP 800-53 Revision 5 - SC-7  
    ](https://csrc.nist.gov/publications/detail/sp/800-53/rev-5/final#sc-7)

## 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.