Data collection
Before you start a study, determine if you have usable data, by collecting this information:
▪Data Input Types
– Server Level (iostat, perfmon, PT Reports)
– Storage Controller Level (DS Storage Manager, IBM Storage Control, IBM i Performance Data Investigator (PDI))
– If using automated input, try to pull a week’s worth of data representing a heavy timeframe such as month-end in
15-minute intervals
▪Selecting modeling inputs – selecting peaks and noticing anomalies
▪Regardless of the data type, there are critical physical disk counters that you need:
– Read IO
– Write IO
– Total IO
– Read Cache Hits
– Read Transfer size (KiB)
– Write Transfer size (KiB)
– Average Transfer size (KiB)