Requested and completed disk I/Os

This data shows the total number of disk I/Os requested and the number and percentage of I/Os completed by each Adaptive Server engine.

“Total Requested Disk I/Os” and “Total Completed I/Os” should be the same or very close. These values will be very different if requested I/Os are not completing due to saturation.

The value for requested I/Os includes all requests that were initiated during the sample interval, and it is possible that some of them completed after the sample interval ended. These I/Os will not be included in “Total Completed I/Os”, and will cause the percentage to be less than 100, when there are no saturation problems.

The reverse is also true. If I/O requests were made before the sample interval began and they completed during the period, you would see a “% of Total” for “Total Completed I/Os” value that is more than 100%.

If the data indicates a large number of requested disk I/Os and a smaller number of completed disk I/Os, there could be a bottleneck in the operating system that is delaying I/Os.