Ubuntu 22.04 LTS – Swap disabled causing OOM kills under load – Fix & Prevention

📖 ~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

Processes are killed by OOM under transient memory spikes.

Environment & Reproduction

Common when swap is disabled on low-memory workloads.

Root Cause Analysis

Without swap headroom, kernel cannot absorb memory spikes and kills processes.

Quick Triage

Confirm swap state and identify high RSS processes.

Step-by-Step Diagnosis

Inspect OOM events and evaluate memory overcommit behavior.

Solution – Primary Fix

Create persistent swapfile and tune swappiness safely.

Solution – Alternative Approaches

Reduce memory footprint or increase RAM allocation for critical hosts.

Verification & Acceptance Criteria

Swap remains active and OOM events stop under typical load.

Rollback Plan

Disable and remove swapfile if policy disallows swap usage.

Prevention & Hardening

Set memory alerting and capacity baselines for peak traffic windows.

Related Errors & Cross-Refs

Related to cgroup memory limits and runaway worker processes.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu swapfile and memory-management documentation.