IBM AIX 7.3 – Common Problem 008 – Diagnosis and Fix

📖 ~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

Client processes hang in uninterruptible D state on NFS-mounted directories.

Environment & Reproduction

IBM AIX 7.3 LPAR exhibiting NFS mount hang / nfsstat issues under standard PowerVM workloads.

mount
nfsstat -m

Root Cause Analysis

NFS server unreachable or lockd/statd not responding causes RPC retransmits.

Quick Triage

Confirm scope with errpt, recent changes, and subsystem state via lssrc.

nfsstat -c
rpcinfo -p nfsserver

Step-by-Step Diagnosis

Validate RPC reachability and inspect nfsstat retransmit counters.

nfsstat -m
rpcinfo -p nfsserver

Solution – Primary Fix

Remount with soft option after stopping NFS client daemons via stopsrc.

stopsrc -g nfs
startsrc -g nfs
mount -o soft /mnt

Solution – Alternative Approaches

Switch to NFSv4 with delegation or migrate to local JFS2 if persistent.

Verification & Acceptance Criteria

Confirm subsystem returns to RUNNING state and errpt shows no new entries.

nfsstat -m
mount | grep nfs

Rollback Plan

Restore prior configuration from mksysb or alt_disk_install clone if the fix regresses.

umount -f /mnt && mount /mnt

Prevention & Hardening

Encode the fix in NIM customisation scripts and monitor via topas/nmon.

no -p -o nfs_socketsize=131072

Related Errors & Cross-Refs

errpt LABEL=NFS_*; lockd statd crash

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

AIX NFS client/server administration