Four way support for dynamic mirror service policy

摘要

Described are techniques for use in determining a dynamic mirror service policy (DMSP) for a plurality of mirror devices. The DMSP determines which of the plurality of mirror devices services I/O operations associated with a logical volume (LV), such as a read operation, at a particular point in time. The particular DMSP may subsequently be recalculated using device statistics from a different time interval. Part of determining a DMSP includes using device statistics to determine the activity level of each LV. The activity levels of multiple LVs may be combined to determine the activity level associated with a particular mirror device. A mirror device is selected if it has the minimum activity of all the plurality of mirror devices. Seek minimization processing is performed to minimize the distance between LVs stored on a single mirror device. Parameters used in connection with determining a DMSP may be stored in a configuration file and may be dynamically modified. Techniques described may also be used in an embodiment having a static MSP.