NetApp "HA GROUP ERROR: DISK/SHELF COUNT MISMATCH ERROR" Troubleshoot

We received an alert “HA GROUP ERROR: DISK/SHELF COUNT MISMATCH ERROR” from the NetApp filer (Model V3240, OS Version 8.1.2 [7-Mode]), one from each node in the NteApp cluster . The alert does not include much information which node has the problem or what goes wrong. It turns out that a disk in one of the nodes start failing. Here are some steps to help to identify the failing disk.

• Option 1: Search CF-Monitor.txt (inside body.7z file attached in the alert) for “Mismatched disk”, and run disk show <disk_device_id>
• Option 2: run disk show -v and look for “FAILED” disk
• Option 3: run sysconfig -d and look for “Not available” under Disk Vital Product Information column
• Option 4: run aggr status -r (or vol status -r) and look for “Maintenance disks”