Patent ID: 7970992

Claim:
A partitioned storage subsystem, comprising: a plurality of directors, each having at least one processor thereon, each of the directors acting as one of: a primary director and a secondary director for a subset of logical devices handled by the partitioned storage subsystem, wherein primary directors actively perform I/O operations for logical devices and wherein secondary directors receive data to mirror memory of an associated primary director; a global memory distributed among the plurality of directors, wherein different portions of the global memory are provided on each of the directors, and wherein the different portions of the global memory are accessible by each of the directors; and metadata for the logical devices, provided in the global memory, wherein the metadata contains information that correlates logical device data with physical device data, wherein, for each of the I/O operations, a particular one of the I/O operations is handled by a corresponding primary director using a portion of the metadata that is provided in the portion of the global memory provided on the corresponding primary director, wherein the portion of the metadata provided on the corresponding primary director corresponds to the particular one of the I/O operations, and wherein, if a different director of the plurality of directors, different from the corresponding primary director, receives a request for the particular one of the I/O operations, although the different director is capable of accessing the portion of the global memory of the corresponding primary director and servicing the particular one of the I/O operations via a non-native global memory access, the different director provides the request to the corresponding primary director having the portion of the global memory that contains the portion of the metadata for servicing the particular one of the I/O operations via a native global memory access.