CONTAP-824327: Potential File Corruption During Automatic Non-Disruptive FlexGroup Volume Rebalancing

On FlexGroup volumes using automatic non-disruptive FlexGroup volume rebalancing, files being rebalanced can lose written data without any error being reported. In a reported case, after a write completed successfully on the client, a 4 KiB (or potentially larger) region of the file later read back as all zeroes. No host-side error and no system event were generated when the data was lost, so the affected files must be identified from application behavior or backup copies.
The affected files had all been recently moved by automatic non-disruptive FlexGroup volume rebalancing between constituents of the FlexGroup volume, and that rebalancing operation is strongly suspected as the cause.