Ubuntu 16.04 LTS – /var reaches 100 percent and services fail

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Logs, package operations, and databases fail when /var has no free space.

Environment & Reproduction

Common on long-lived systems with log growth and unattended artifact accumulation.

Root Cause Analysis

Runaway logs, cache buildup, or orphaned data consume critical writable capacity.

Quick Triage

Identify top consumers in /var and assess immediate risk to core services.

Step-by-Step Diagnosis

Profile disk usage by directory and locate abnormal growth patterns.

Solution – Primary Fix

Free safe space, rotate logs, clear caches, and restore write headroom.

Solution – Alternative Approaches

Expand partition or relocate heavy paths to larger dedicated volumes.

Verification & Acceptance Criteria

Critical services recover and sustained free space remains above operational threshold.

Rollback Plan

Restore archived logs and prior mount layout if cleanup removes required files.

Prevention & Hardening

Set quotas and alerting for growth rates on /var and application logs.

Related Errors & Cross-Refs

No space left on device and write failed errors confirm storage exhaustion.

Related tutorial: View the step-by-step tutorial for Ubuntu 16.04 LTS.

View all Ubuntu 16.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Consult logrotate and Ubuntu filesystem capacity planning best practices.