The Oracle FS System collects an extensive set of statistics that cover many aspects of the performance of the overall system, including data usage.
The Oracle FS System monitors and analyzes the data activity statistics of the LUN to determine if the initial properties make the best use of the available storage resources. If, for example, the system determines that data within a LUN has not been accessed for several days, the system moves 640 KB blocks of data from the LUN to high-capacity, low-cost drives that are suitable for archival purposes. If the volume experiences a high amount of data activity, the Oracle FS System migrates the LUN data to higher-performance drives.
For a LUN that is using QoS Plus, the Oracle FS System gathers and stores statistics about the access requests as I/O is performed on the LUN. At specific times, which can be set by the administrator for a Storage Domain, the system analyzes those statistics. From this analysis, if the system determines that certain data within the auto-tiered LUN can benefit by placing the data on a different storage tier, the system migrates that data to the storage tier that best matches the use of the data.