Ubuntu 14.04 LTS excessive swap usage causes severe slowdown

📖 ~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

Interactive and batch workloads become slow and unresponsive.

Environment & Reproduction

Observed on memory-constrained hosts under peak application load.

Root Cause Analysis

RAM exhaustion pushes active pages to swap, increasing IO latency.

Quick Triage

Inspect free, vmstat, and top to confirm swap thrashing pattern.

Step-by-Step Diagnosis

Identify top memory consumers and reclaimable cache behavior.

Solution – Primary Fix

Tune swappiness, reduce memory footprint, and add RAM if required.

Solution – Alternative Approaches

Apply workload limits and schedule heavy jobs off-peak.

Verification & Acceptance Criteria

Swap growth stabilizes and latency returns to baseline.

Rollback Plan

Revert sysctl values if application behavior worsens unexpectedly.

Prevention & Hardening

Set memory alerts and right-size instances for sustained load.

Related Errors & Cross-Refs

kswapd high CPU and application timeout symptoms.

Related tutorial: View the step-by-step tutorial for Ubuntu 14.04 LTS.

View all Ubuntu 14.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Linux memory tuning documentation for long-lived servers.