📖 ~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

System reports no space left on device; services fail to write temp files and logs.

Environment & Reproduction

Ubuntu 18.04 VMs with small root volumes and growing logs, caches, or container layers.

Root Cause Analysis

Unbounded growth in /var/log, apt cache, snaps, or application data exhausts root partition.

Quick Triage

Use df -h and sudo du -xhd1 / to find largest directories quickly.

Step-by-Step Diagnosis

Inspect /var/log, /var/lib/snapd, /var/cache/apt, and orphaned files held by deleted processes using lsof +L1.

Illustrative mockup for ubuntu-18-04-lts — ubuntu1804-root-disk-full-diagnose.webp
Locating top disk consumers on root filesystem — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Run apt clean, journalctl vacuum, remove unused snaps revisions, and rotate/compress oversized logs.

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Illustrative mockup for ubuntu-18-04-lts — ubuntu1804-root-disk-full-fix.webp
Cleaning packages, logs, and caches on Ubuntu 18.04 — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Extend disk/LVM volume or relocate high-growth paths like Docker data to a dedicated partition.

Verification & Acceptance Criteria

At least 15-20 percent free space is restored and critical services recover normal operation.

Rollback Plan

Restore purged data from backups when retention requirements were impacted.

Prevention & Hardening

Set filesystem usage alerts, enforce log retention policies, and schedule periodic cleanup tasks.

No space left on device, tmp write failures, and package unpack errors.

Related tutorial: View the step-by-step tutorial for Ubuntu 18.04 LTS.

View all Ubuntu 18.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

man du, man df, Ubuntu logrotate docs, and apt cache management.

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