Ubuntu 24.04 LTS – root filesystem full causes service failures – 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

System services fail to start or write logs because root filesystem is full.

Environment & Reproduction

Frequent on hosts with unbounded logs, package cache growth, or old kernels.

df -h
sudo du -xh / --max-depth=1 | sort -h

Root Cause Analysis

Disk usage growth exceeded available space on critical partitions.

Quick Triage

Find top consumers and clear safe temporary targets first.

sudo du -xh /var --max-depth=2 | sort -h | tail -n 20
sudo journalctl --disk-usage

Step-by-Step Diagnosis

Measure package cache, logs, and old kernel footprint.

sudo apt clean
ls -1 /boot | wc -l
dpkg -l 'linux-image-*' | grep '^ii'

Solution – Primary Fix

Free space by cleaning cache, pruning journals, and removing obsolete kernels.

sudo apt clean
sudo journalctl --vacuum-time=7d
sudo apt autoremove --purge -y
df -h

Solution – Alternative Approaches

Expand disk or LVM volume when cleanup cannot meet growth demands.

lsblk
sudo pvdisplay 2>/dev/null || true

Verification & Acceptance Criteria

At least 15 percent free space on root and service restarts succeed.

df -h /
sudo systemctl --failed

Rollback Plan

Restore archived logs if retention requirements were exceeded during emergency cleanup.

sudo tar -tf /var/backups/log-archive.tar.gz | head

Prevention & Hardening

Set log retention and capacity alarms before disk pressure impacts services.

sudoedit /etc/systemd/journald.conf
sudo systemctl restart systemd-journald

Related Errors & Cross-Refs

Related errors include No space left on device and failed to write log output.

Related tutorial: View the step-by-step tutorial for Ubuntu 24.04 LTS.

View all Ubuntu 24.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu storage management and systemd-journald retention references.