# Ensure /var/tmp Directory is Mounted on a Separate Partition

- Source: https://support.icompaas.com/support/solutions/articles/62000234976-ensure-var-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 2

**Description:**  
 The /var/tmp directory is used for temporary files that are preserved between system reboots. Mounting /var/tmp on a separate partition isolates temporary files from other system directories, improving system stability and security.

**Rationale:** Having /var/tmp on a separate partition limits the impact of disk space exhaustion or filesystem corruption to temporary files only. It also enables specific mount options to enhance security and prevent denial-of-service conditions affecting other filesystems.

**Impact:** Pros:

-   Isolates temporary files from critical system and user data.  
    
-   Prevents disk space exhaustion on root or other partitions.  
    
-   Facilitates application of secure mount options.  
    

Cons:

-   Requires additional partitioning and disk space allocation.  
    
-   Incorrect configuration may cause system or application issues.  
    

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

**Pre-requisites:**

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

**Remediation:**

### **Test Plan:**

**Using Linux command line:**

1.  Check current mount points for /var/tmp:  
    
     mount | grep /var/tmp
    
2.  Verify if /var/tmp is mounted separately:  
    
     findmnt /var/tmp
    
3.  Check /etc/fstab for /var/tmp entry:  
    
     grep /var/tmp /etc/fstab
    
    Expected output: /var/tmp should be listed as a separate mount point.
    

  

### **Implementation Plan:**

**Using Linux command line:**

1.  Create a separate partition or logical volume for /var/tmp.  
    
2.  Format the partition:  
    
     mkfs.ext4 /dev/<partition>
    
3.  Backup existing /var/tmp data:  
    
     cp -a /var/tmp /var/tmp\_backup
    
4.  Mount new partition temporarily:  
    
     mount /dev/<partition> /mnt
    
5.  Copy backup data back:  
    
     cp -a /var/tmp\_backup/\* /mnt/
    

6.  Add /var/tmp entry in /etc/fstab with secure mount options, for example:  
    
    /dev/<partition>  /var/tmp  ext4  defaults,nodev,nosuid,noexec  0  0
    
7.  Unmount temporary mount:  
    
     umount /mnt
    
8.  Mount /var/tmp:  
    
     mount /var/tmp
    
      
    
9.  Verify mount and permissions.  
      
    

### **Backout Plan:**

**Using Linux command line:**

1.  Remove or comment out /var/tmp entry in /etc/fstab.  
    
2.  Unmount /var/tmp:  
    
     umount /var/tmp
    
3.  Restore backup if needed:  
    
     cp -a /var/tmp\_backup/\* /var/tmp/
    
4.  Reboot 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)
    

---

Tags:  
, , , ,

## 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.