Disk Full on Root or /var Breaks Services

📖 ~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

Full disks can halt writes for databases, logs, and package operations.

Environment & Reproduction

Services crash or become read-only; apt and journald report no space left.

Root Cause Analysis

Hosts with small root volumes, runaway logs, or orphaned artifacts.

Quick Triage

Unexpected growth in logs, caches, backups, or application temp files.

Step-by-Step Diagnosis

Capture top disk consumers with df, du, and journal size stats.

Solution – Primary Fix

Purge safe cache and archive logs to restore free space quickly.

Solution – Alternative Approaches

Implement retention policies and right-size partitions for workload growth.

Verification & Acceptance Criteria

Validate free space thresholds and stable service restarts.

Rollback Plan

Set quotas, cleanup jobs, and lifecycle policies for temp artifacts.

Prevention & Hardening

Alert at 75 percent and 90 percent utilization for critical mount points.

Related Errors & Cross-Refs

Reattach archived data only after expanding capacity or offloading storage.

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 storage administration docs and journald size controls.