GNOME Login Loop After Disk Full

📖 ~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

Successful credential entry returns to login screen repeatedly, blocking desktop access.

Environment & Reproduction

Ubuntu 20.04 GNOME systems where root or home filesystem reaches 100% usage.

Root Cause Analysis

Session components cannot create required runtime files, causing immediate display manager reset.

Quick Triage

Enter TTY, check filesystem utilization, and inspect session logs for write failures.

Step-by-Step Diagnosis

Locate largest directories, temporary growth sources, and ownership/permission anomalies.

Solution – Primary Fix

Free critical space, repair runtime directory permissions, then restart GDM and log in.

Solution – Alternative Approaches

Move large data to secondary storage or extend volume/LVM allocation.

Verification & Acceptance Criteria

User session starts normally and desktop applications launch without immediate logout.

Rollback Plan

Restore deleted data from backup if cleanup removed needed files unexpectedly.

Prevention & Hardening

Set disk alerts, journal retention limits, and periodic cleanup for cache/temp paths.

Related Errors & Cross-Refs

`No space left on device`, failing user service startup, and `.Xauthority` write errors.

Related tutorial: View the step-by-step tutorial for Ubuntu 20.04 LTS.

View all Ubuntu 20.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu disk management and GNOME session troubleshooting documentation.