ALR0592E The Non-preferred Node Usage Percentage of I/O Group I/O Group name in device device name was measured to be measured value%, which violated the critical-stress boundary value of boundary value%.
Explanation
Non-preferred Node Usage Percentage measures the approximate percentage of I/O operations that are not directed against the preferred node for each volume in an I/O Group. There is a small performance penalty when I/O does not go to the preferred node for each volume. A threshold was defined on this metric, which causes the measured value to be compared to the defined boundaries for each set of performance statistics collected from the storage system.
This message indicates that a threshold boundary violation occurred. In this case, the specified I/O Group in the storage system has a Non-preferred Node Usage Percentage value that is greater than or equal to the critical-stress boundary that was defined for the related threshold.
Action
Under normal conditions, the non-preferred node usage percentage should be zero for all I/O groups. The threshold violation might indicate either that a configuration problem exists for some of the host servers using storage from the storage system, or that some of the data paths from the host servers to the storage system through the fabric are currently not operational.
To determine which volumes are the culprit, the Non-preferred Node Usage Percentage metric is also available for volumes. The hosts that are using these volumes may not have multi-pathing software installed or configured properly, such that volume I/O is being directed to the non-preferred node of the I/O Group. Or if the host does not have redundant data paths to the storage system, it is possible that the host was connected or zoned to the incorrect node of the I/O Group. Correcting these configuration errors will usually resolve the problem.