Disclosed are a storage controller, and a method of operating a storage
controller, for interfacing between host systems and a storage devices
system. The storage controller includes a first cluster including a first
processor and a first cache, and a second cluster including a second
processor and a second cache. The method comprises the step of directing
data from the host systems through first and second data paths to the
storage system. The first processor and cache are associated with the
first data path, and the second processor and cache are associated with
the second data path. Under one set of conditions, the controller enters
a failover mode, wherein data directed to the first data path are routed
to the second data path. Under another set of conditions, the controller
deconfigures the first cache without entering the failover mode.