Periodic destages from inside and outside diameters of disks to improve read response times

A method, comprising:

• receiving, by a storage controller that includes a cache, a command from a host, wherein a set of criteria corresponding to read response times for executing the command have to be satisfied;
• executing a destage application that destages tracks based at least on recency of usage and spatial location of the tracks, wherein a spatial ordering of the tracks is maintained in a data structure, and the destage application traverses the spatial ordering of the tracks;
• and
• destaging tracks from at least inside or outside diameters of disks at periodic intervals, while traversing the spatial ordering of the tracks, wherein the set of criteria corresponding to the read response times for executing the command are satisfied, wherein the method further comprises:
• setting a timer to a predetermined time interval and setting a destage counter to zero;
• and picking up a track at a cursor position to destage while traversing the data structure that maintains the spatial ordering of the tracks.