Method, apparatus, and program for detecting sequential and distributed path errors in MPIO

An error detection mechanism is provided for detecting sequential and distributed errors in a device I/O stream. The sensitivity of the errors is user definable. The result of the error detection is fed back into the path management software, which may use the error information to decide whether a device path should be disabled. The error detection mechanism sets a time span for a time window and counts the number of errors that occur during the time window. Each time a time window ends with at least one error, the sequential error count and the distributed error count are incremented. However, if an I/O returns without an error, the sequential error count is cleared. If the sequential error count reaches a predetermined limit, the path is disabled. After a predetermined number of time windows, if the distributed error count reaches a predetermined limit, the path is disabled.