Enhanced QoS, called QoS Plus, automatically adapts the location of data blocks to optimize the storage efficiencies, to yield a higher performance, and to lower the cost of storage. The QoS Plus features result in an optimal cost/IOP and the cost/TB over time by means of specific usage characteristics and specific QoS levels.
When configuring QoS Plus for a LUN (by selecting the Auto-tier option), the administrator configures the initial settings for the LUN and then lets the system manage the placement of the data from that point forward. Besides initially creating the auto-tiered LUN, an administrator needs to adjust little else, if anything, after the LUN is created.