Debian 11 Disk Full in /var Causes Service Outages

📖 ~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

Critical services fail to write state, logs, or pid files due to full /var.

Environment & Reproduction

Usually appears with runaway logs, cache growth, or orphaned package files.

Root Cause Analysis

Uncontrolled write growth exhausts capacity or inode availability in /var.

Quick Triage

Measure capacity and inode pressure and identify top growth paths quickly.

Step-by-Step Diagnosis

Profile large directories and recent growth to isolate primary offenders.

Solution – Primary Fix

Free space safely, rotate or purge stale data, and restore service write paths.

Solution – Alternative Approaches

Expand the filesystem or move high-volume data paths to dedicated storage.

Verification & Acceptance Criteria

Capacity remains within threshold and impacted services return to healthy state.

Rollback Plan

Recover archived data from backup if cleanup removed needed artifacts.

Prevention & Hardening

Enforce retention policies and disk-usage alerts for /var growth domains.

Related Errors & Cross-Refs

Often linked with journald growth, apt cache bloat, and database write failures.

Related tutorial: View the step-by-step tutorial for Debian 11.

View all Debian 11 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Debian storage management and log-retention documentation.