Disk service time by drive. This is the time it takes for a disk read or write to complete. For example, if the service time for one drive runs from 12 to 25 milliseconds, this indicates it is SCSI technology. Read Hit Percentage. The percentage of time that disk read requests were satisfied in main memory.
High values are desirable.
Figure 4 shows the thresholds for the green, yellow, and red zones, and is an example of red zone performance on the read hit percentage. Figures 3 and 4 reveal a general yellow to red zone for data locality. This means that the operating system prefetch mechanism will be able to eliminate disk accesses if data is grouped in such a way that many users share much of the data. CPU Pause for Disk. CPU paused for disk can be caused by poor data locality and means that the CPU had to wait instead of work.