Debian 10 – Swap inactive after reboot causing OOM events – 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

Memory pressure spikes and services terminate from OOM killer activity.

Environment & Reproduction

Observed after storage migration or swap UUID/path changes.

Root Cause Analysis

Swap entry is invalid or missing from startup configuration.

Quick Triage

Check active swap with `swapon –show` and free memory with `free -h`.

Step-by-Step Diagnosis

Verify swap UUID in `/etc/fstab` and inspect boot logs for mount/activation errors.

Solution – Primary Fix

Recreate or re-register swap, update fstab, and activate via `sudo swapon -a`.

Solution – Alternative Approaches

Create a temporary swapfile with controlled permissions as interim mitigation.

Verification & Acceptance Criteria

Swap is active after reboot and OOM events stop under normal load.

Rollback Plan

Restore prior fstab and disable temporary swapfile if performance regresses.

Prevention & Hardening

Validate swap activation in post-change boot checks.

Related Errors & Cross-Refs

Related to low memory tuning and aggressive container memory limits.

Related tutorial: View the step-by-step tutorial for debian-10.

View all debian-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Debian memory management and swap administration docs.