📖 ~1 min read
Table of contents
Symptom & Impact
Applications fail with `ENOSPC` even though `df` shows free space on `/data`.
Environment & Reproduction
AIX 7.2 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`.

Solution – Primary Fix
Delete the full snapshot: `snapshot -d /dev/snap00` then resume writes on `/data`.
Still having issues? Our IT Solutions & Services team can diagnose and resolve this for you. Get in touch for a free consultation.

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`.
Related Errors & Cross-Refs
Pairs with `J2_FS_FULL` and stuck `syncd` flushes on heavy write workloads.
Related tutorial: View the step-by-step tutorial for aix-7.1.
View all aix-7.1 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`.
Need Expert Help?
If you cannot resolve this yourself, our team offers hands-on Server Management, Managed IT Services, and flexible Support Plans. Contact us today — we respond within one business day.