LVM Filesystem Full Despite Free Space in VG

📖 ~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

Applications fail with `No space left on device` even though volume group has available capacity.

Environment & Reproduction

After rapid data growth where logical volume extension was never performed post-deployment.

Root Cause Analysis

Filesystem not resized, wrong LV targeted for growth, or mountpoint mapping misunderstood.

Quick Triage

Run `df -h`, `lvs`, `vgs`, and verify LV-to-mount mapping with `lsblk -f`.

Step-by-Step Diagnosis

Use `lvdisplay`, `xfs_info `, `findmnt `, and `journalctl -p err –since -2h`.

Solution – Primary Fix

Logical volume and filesystem sizes increase, and application writes succeed immediately.

Solution – Alternative Approaches

Extend LV and filesystem online (`lvextend` + `xfs_growfs` for XFS) during controlled maintenance.

Verification & Acceptance Criteria

Re-run `df -h`, create test files, and confirm application queues/processes recover from prior failures.

Rollback Plan

If extension targeted wrong LV, restore from snapshot/backup because shrinking XFS is unsupported.

Prevention & Hardening

Monitor filesystem growth trends and auto-ticket capacity actions before critical thresholds.

Related Errors & Cross-Refs

`lvextend -r -L +20G /dev/vgdata/lvdata && df -h /data`

Related tutorial: View the step-by-step tutorial for rhel-8.

View all rhel-8 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

RHEL 8 LVM and XFS administration docs with online expansion procedures and caveats.