🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026
Affected versions: IBM AIX 7.3

📖 ~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 `ENOSPC` even though `df` shows free space on `/data`.

Environment & Reproduction

AIX 7.3 JFS2 filesystem `/data` with an external snapshot that has filled to 100%.

Root Cause Analysis

Snapshot LV reached capacity; writes to the base FS are blocked to protect snapshot consistency.

Quick Triage

Run `snapshot -q /data`, `lsfs -q /data`, and `df -k /data` to see snapshot fill.

Step-by-Step Diagnosis

Capture `errpt | grep J2_SNAP` and identify the snap LV with `lsvg -l rootvg`.

Illustrative mockup for aix-7.3 — fs_jfs2-snapshot-full_terminal
Terminal diagnostics for JFS2 snapshot space exhausted on IBM AIX 7.3 — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Delete the full snapshot: `snapshot -d /dev/snap00` then resume writes on `/data`.

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Illustrative mockup for aix-7.3 — fs_jfs2-snapshot-full_logs
Logs and evidence for JFS2 snapshot space exhausted on IBM AIX 7.3 — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Grow the snapshot LV: `chlv -x snap00` and re-mount the snapshot.

Verification & Acceptance Criteria

`snapshot -q /data` returns under 80% used and application writes succeed again.

Rollback Plan

Recreate the prior snapshot with `snapshot -o snapfrom=/data -o size=…`.

Prevention & Hardening

Schedule snapshot rotation and monitor with `errnotify` on `J2_SNAP_FULL`.

Pairs with `J2_FS_FULL` and stuck `syncd` flushes on heavy write workloads.

Related tutorial: View the step-by-step tutorial for aix-7.3.

View all aix-7.3 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

IBM Docs: JFS2 snapshots, `snapshot`, `chfs -a size`.

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