Updating Performance Profiles
Performance profiles are used to characterize response times, I/Os per second, MBs per second, and cache hits per second as Poor, Normal, and Fast. Creation of and updating Performance Profiles establishes the criteria used based on performance and throughput metrics captured within a profile interval, using the following logic:
1. For all LUNs with performance data captured during the specified performance interval, group the data based on common physical attributes: array vendor, array family, array model, RAID type, number of drives in RAID Group, drive type, drive form, and drive speed. Each unique grouping of LUNs based on this criteria represents an individual APTARE IT Analytics Performance reporting profile entry for this Portal.
2. Calculate the average and standard deviation for all captured metrics based on all LUNs with performance data in the specified interval and within a common performance profile. When there is more than one poll to the array during the profile updating interval, averages and standard deviation will be based on only the portion of the interval covered for the polls that return data, ignoring polls that did not capture I/Os or where the response times were zero.
3. To determine boundaries within the range, subtract one standard deviation from the average. If the standard deviation is larger than the average, divide the average by two. This establishes the low end of the Normal boundary and the high end of the Fast boundary.
4. Add one standard deviation to the average. If the standard deviation is larger than the average, add half of the average to the average. This establishes the high end of the Normal boundary and the low end of the Poor boundary.